Wireless transmission to satellites for multichannel audio system

ABSTRACT

Some disclosed systems and methods include assigning channel streams to satellite playback devices, delaying initial transmission of surround sound content to satellite playback devices to accumulate audio samples for transmission in individual frames of surround sound content, and taking advantage of configured playback delays for different channels of surround sound content to prioritize transmission of channels of surround sound content having shorter configured playback delays over transmission of channels of surround sound content having longer configured playback delays.

FIELD OF THE DISCLOSURE

The present disclosure is related to consumer goods and, moreparticularly, to methods, systems, products, features, services, andother elements directed to media playback and aspects thereof, includingsurround sound media.

BACKGROUND

Options for accessing and listening to digital audio in an out-loudsetting were limited until in 2002, when SONOS, Inc. began developmentof a new type of playback system. Sonos then filed one of its firstpatent applications in 2003, entitled “Method for Synchronizing AudioPlayback between Multiple Networked Devices,” and began offering itsfirst media playback systems for sale in 2005. The Sonos Wireless HomeSound System enables people to experience music from many sources viaone or more networked playback devices. Through a software controlapplication installed on a controller (e.g., smartphone, tablet,computer, voice input device), one can play what she wants in any roomhaving a networked playback device. Media content (e.g., songs,podcasts, video sound) can be streamed to playback devices such thateach room with a playback device can play back corresponding differentmedia content. In addition, rooms can be grouped together forsynchronous playback of the same media content, and/or the same mediacontent can be heard in all rooms synchronously.

BRIEF DESCRIPTION OF THE DRAWINGS

Features, aspects, and advantages of the presently disclosed technologymay be better understood with regard to the following description,appended claims, and accompanying drawings, as listed below. A personskilled in the relevant art will understand that the features shown inthe drawings are for purposes of illustrations, and variations,including different and/or additional features and arrangements thereof,are possible.

FIG. 1A shows a partial cutaway view of an environment having a mediaplayback system configured in accordance with aspects of the disclosedtechnology.

FIG. 1B shows a schematic diagram of the media playback system of FIG.1A and one or more networks.

FIG. 1C shows a block diagram of a playback device.

FIG. 1D shows a block diagram of a playback device.

FIG. 1E shows a block diagram of a network microphone device.

FIG. 1F shows a block diagram of a network microphone device.

FIG. 1G shows a block diagram of a playback device.

FIG. 1H shows a partially schematic diagram of a control device.

FIGS. 1-I through 1L show schematic diagrams of corresponding mediaplayback system zones.

FIG. 1M shows a schematic diagram of media playback system areas.

FIG. 2A shows a front isometric view of a playback device configured inaccordance with aspects of the disclosed technology.

FIG. 2B shows a front isometric view of the playback device of FIG. 3Awithout a grille.

FIG. 2C shows an exploded view of the playback device of FIG. 2A.

FIG. 3A shows a front view of a network microphone device configured inaccordance with aspects of the disclosed technology.

FIG. 3B shows a side isometric view of the network microphone device ofFIG. 3A.

FIG. 3C shows an exploded view of the network microphone device of FIGS.3A and 3B.

FIG. 3D shows an enlarged view of a portion of FIG. 3B.

FIG. 3E shows a block diagram of the network microphone device of FIGS.3A-3D

FIG. 3F shows a schematic diagram of an example voice input.

FIGS. 4A-4D show schematic diagrams of a control device in variousstages of operation in accordance with aspects of the disclosedtechnology.

FIG. 5 shows front view of a control device.

FIG. 6 shows a message flow diagram of a media playback system.

FIG. 7 shows an example configuration of a multichannel audio systemaccording to some embodiments.

FIG. 8 an example timing diagram for generating and transmittingsurround sound audio information to satellites for a multichannelsurround sound audio system according to some embodiments.

FIG. 9 shows an example method for generating and transmitting surroundsound audio information to satellites for a multichannel surround soundaudio system according to some embodiments.

The drawings are for the purpose of illustrating example embodiments,but those of ordinary skill in the art will understand that thetechnology disclosed herein is not limited to the arrangements and/orinstrumentality shown in the drawings.

DETAILED DESCRIPTION I. Overview

Surround sound systems with satellite speakers distributed within alistening area can provide listeners with a highly immersive multimediaexperience when (i) listening to music, (ii) playing video games, and/or(iii) watching television, movies, and/or other video or multimediacontent. Wireless surround sound systems are desirable because thesatellite speakers can be implemented quickly and easily without theneed to run speaker cabling throughout the room to connect the satellitespeakers to a central surround sound processor, such a soundbar, anaudio tuner, audio/video head end, or other central surround soundprocessor. Additionally, wireless surround sound systems can be upgradedto add more satellites more easily than wired systems because existingsatellites can be repurposed/repositioned (e.g., reconfiguring a rearsatellite to function as a side satellite) within a room as newsatellites are added to the system over time.

However, technical challenges arise when implementing wireless surroundsound systems having more than 5-7 surround sound channels played backby more than about 3 satellite speakers or playback devices. Inparticular, for surround sound content that has corresponding videocontent, it is important for the surround sound system to process anddistribute the multiple channels of surround sound content to all thesatellite playback devices in the surround sound system for furtherprocessing and playback sufficiently quickly to ensure that the surroundsound content collectively played by the surround sound system does notis not perceived to be out of sync with the corresponding video content.In addition to playing the surround sound content in sync with (or atleast substantially in sync with) its corresponding video content, thevarious playback devices (headend devices and satellite devices) in thesurround sound system should also play back their respective portions ofthe surround sound content in synchrony with each other so that thesurround sound content does not have undesirable echo effects. Butbecause of the processing and transmission time required to generate anddistribute higher channel-count surround sound content among a largernumber of satellite playback devices, it can be difficult for a headenddevice (e.g., a soundbar, audio/video tuner, or other device equippedwith a surround sound processor) to process incoming surround soundcontent and distribute the surround sound content among multiplesatellite playback devices of the surround sound system sufficientlyfast in a real-time or substantially real-time manner so that thesurround sound system can play the surround sound content both (i) insynchrony and (ii) in sync with corresponding video content.

The problems are further compounded in surround sound systems whereindividual playback devices are also configured to receive and processvoice commands, e.g., requesting content for playback by the surroundsound system and other voice requests, because of the additionalprocessing load placed on the playback device to process the voicecommands and the additional data that must be transmitted across the LANin connection with processing these requests, particularly in view ofthe quick response times expected by users.

The systems and methods disclosed and described herein overcome theseand other technical challenges that can arise with wirelessmulti-channel surround sound systems. In some embodiments, the systemsand methods include assigning channel streams to satellite playbackdevices, delaying initial transmission of surround sound content tosatellite playback devices to accumulate more audio samples fortransmission in individual frames of surround sound content, and takingadvantage of configured playback delays for different channels ofsurround sound content to prioritize transmission of channels ofsurround sound content having shorter configured playback delays overtransmission of channels of surround sound content having longerconfigured playback delays.

For example, in some embodiments, a soundbar (or similar headendcontroller comprising a surround sound processor or similar processingcapability) processes incoming surround sound content to generate aplurality of channel streams for organizing multiple channels ofsurround sound content for distribution among and playback by aplurality of wireless satellite playback devices. Some individualchannel streams may comprise multiple subchannels, where each subchannelcomprises a portion of the surround sound content corresponding to anindividual surround sound channel for playback by playback device. Forexample, a channel stream for a rear satellite playback deviceconfigured to play a right rear channel and a right overhead channel mayinclude a first subchannel for the rear right channel audio and a secondsubchannel for the rear right overhead audio. Some channel streams maycomprise only a single channel of surround sound audio. For example, achannel stream for a subwoofer satellite playback device configured toplay a single subwoofer channel may include only the subwoofer audio.

In operation, some embodiments include, after an initial delay periodafter beginning the generation of a plurality of channel streamscomprising surround audio information, and during a first time interval,the soundbar, (i) for each satellite playback device in a first set ofsatellite playback devices, generates a first portion of a channelstream for the satellite playback device, and (ii) for each satelliteplayback device in a second set of satellite playback devices, generatesa first portion of a channel stream for the satellite playback device.And during a second time interval following the first time interval, thesoundbar (i) for each satellite playback device in the first set ofsatellite playback devices, generates a second portion of the channelstream for the satellite playback device, and (ii) for each satelliteplayback device in the second set of satellite playback devices,generates a second portion of the channel stream for the satelliteplayback device. And during a third time interval following the secondtime interval, the soundbar (i) for each satellite playback device inthe first set of playback devices, generates a third portion of thechannel stream for the satellite playback device and transmits the firstportion and the second portion of the channel stream to the satelliteplayback device via the LAN and (ii) for each satellite playback devicein the second set of satellite playback devices, generates a thirdportion of the channel stream for the satellite playback device. Andduring a fourth time interval following the third time interval, thesoundbar (i) for each satellite playback device in the first set ofsatellite playback devices, generates a fourth portion of the channelstream for the satellite playback device and (ii) for each satelliteplayback device in the second set of satellite playback devices,generates a fourth portion of the channel stream for the satelliteplayback device and transmits the second portion and the third portionof the channel stream to the satellite playback device.

Although implementing a short delay after beginning the generation of aplurality of channel streams comprising surround audio informationintroduces an otherwise undesirable delay in the overall playback schemeby reducing the amount of time available to transmit the frames of thechannel streams to the satellite playback devices and for the satelliteplayback devices to receive, process, and play the surround sound audioinformation within the frames of their channel streams as describedherein, the short delay enables the headend processor (e.g., a soundbaror similar) to accumulate more audio samples to transmit to eachsatellite playback device, thereby improving the transmission efficiencyof the system by transmitting more audio samples per frame than simplytransmitting frames as they are generated (or more quickly aftergeneration). Implementing the short delay between frame generation andframe transmission also enables the headend (e.g., the soundbar orsimilar) to distribute frames of audio to individual satellite playbackdevices in a way that prioritizes channels of audio content that are tobe played earlier than other channels.

While some examples described herein may refer to functions performed bygiven actors such as “users,” “listeners,” and/or other entities, itshould be understood that this is for purposes of explanation only. Theclaims should not be interpreted to require action by any such exampleactor unless explicitly required by the language of the claimsthemselves.

In the figures, identical reference numbers identify generally similar,and/or identical, elements. To facilitate the discussion of anyparticular element, the most significant digit or digits of a referencenumber refers to the Figure in which that element is first introduced.For example, element 110 a is first introduced and discussed withreference to FIG. 1A. Many of the details, dimensions, angles and otherfeatures shown in the Figures are merely illustrative of particularembodiments of the disclosed technology. Accordingly, other embodimentscan have other details, dimensions, angles and features withoutdeparting from the spirit or scope of the disclosure. In addition, thoseof ordinary skill in the art will appreciate that further embodiments ofthe various disclosed technologies can be practiced without several ofthe details described below.

II. Suitable Operating Environment

FIG. 1A is a partial cutaway view of a media playback system 100distributed in an environment 101 (e.g., a house). The media playbacksystem 100 comprises one or more playback devices 110 (identifiedindividually as playback devices 110 a-n), one or more networkmicrophone devices (“NMDs”), 120 (identified individually as NMDs 120a-c), and one or more control devices 130 (identified individually ascontrol devices 130 a and 130 b).

As used herein the term “playback device” can generally refer to anetwork device configured to receive, process, and output data of amedia playback system. For example, a playback device can be a networkdevice that receives and processes audio content. In some embodiments, aplayback device includes one or more transducers or speakers powered byone or more amplifiers. In other embodiments, however, a playback deviceincludes one of (or neither of) the speaker and the amplifier. Forinstance, a playback device can comprise one or more amplifiersconfigured to drive one or more speakers external to the playback devicevia a corresponding wire or cable.

Moreover, as used herein the term NMD (i.e., a “network microphonedevice”) can generally refer to a network device that is configured foraudio detection. In some embodiments, an NMD is a stand-alone deviceconfigured primarily for audio detection. In other embodiments, an NMDis incorporated into a playback device (or vice versa).

The term “control device” can generally refer to a network deviceconfigured to perform functions relevant to facilitating user access,control, and/or configuration of the media playback system 100.

Each of the playback devices 110 is configured to receive audio signalsor data from one or more media sources (e.g., one or more remoteservers, one or more local devices) and play back the received audiosignals or data as sound. The one or more NMDs 120 are configured toreceive spoken word commands, and the one or more control devices 130are configured to receive user input. In response to the received spokenword commands and/or user input, the media playback system 100 can playback audio via one or more of the playback devices 110. In certainembodiments, the playback devices 110 are configured to commenceplayback of media content in response to a trigger. For instance, one ormore of the playback devices 110 can be configured to play back amorning playlist upon detection of an associated trigger condition(e.g., presence of a user in a kitchen, detection of a coffee machineoperation). In some embodiments, for example, the media playback system100 is configured to play back audio from a first playback device (e.g.,the playback device 100 a) in synchrony with a second playback device(e.g., the playback device 100 b). Interactions between the playbackdevices 110, NMDs 120, and/or control devices 130 of the media playbacksystem 100 configured in accordance with the various embodiments of thedisclosure are described in greater detail below with respect to FIGS.1B-1L.

In the illustrated embodiment of FIG. 1A, the environment 101 comprisesa household having several rooms, spaces, and/or playback zones,including (clockwise from upper left) a master bathroom 101 a, a masterbedroom 101 b, a second bedroom 101 c, a family room or den 101 d, anoffice 101 e, a living room 101 f, a dining room 101 g, a kitchen 101 h,and an outdoor patio 101 i. While certain embodiments and examples aredescribed below in the context of a home environment, the technologiesdescribed herein may be implemented in other types of environments. Insome embodiments, for example, the media playback system 100 can beimplemented in one or more commercial settings (e.g., a restaurant,mall, airport, hotel, a retail or other store), one or more vehicles(e.g., a sports utility vehicle, bus, car, a ship, a boat, an airplane),multiple environments (e.g., a combination of home and vehicleenvironments), and/or another suitable environment where multi-zoneaudio may be desirable.

The media playback system 100 can comprise one or more playback zones,some of which may correspond to the rooms in the environment 101. Themedia playback system 100 can be established with one or more playbackzones, after which additional zones may be added, or removed to form,for example, the configuration shown in FIG. 1A. Each zone may be givena name according to a different room or space such as the office 101 e,master bathroom 101 a, master bedroom 101 b, the second bedroom 101 c,kitchen 101 h, dining room 101 g, living room 101 f, and/or the patio101 i. In some aspects, a single playback zone may include multiplerooms or spaces. In certain aspects, a single room or space may includemultiple playback zones.

In the illustrated embodiment of FIG. 1A, the master bathroom 101 a, thesecond bedroom 101 c, the office 101 e, the living room 101 f, thedining room 101 g, the kitchen 101 h, and the outdoor patio 101 i eachinclude one playback device 110, and the master bedroom 101 b and theden 101 d include a plurality of playback devices 110. In the masterbedroom 101 b, the playback devices 110 l and 110 m may be configured,for example, to play back audio content in synchrony as individual onesof playback devices 110, as a bonded playback zone, as a consolidatedplayback device, and/or any combination thereof. Similarly, in the den101 d, the playback devices 110 h-j can be configured, for instance, toplay back audio content in synchrony as individual ones of playbackdevices 110, as one or more bonded playback devices, and/or as one ormore consolidated playback devices. Additional details regarding bondedand consolidated playback devices are described below with respect to,for example, FIGS. 1B and 1E and 1I-1M.

In some aspects, one or more of the playback zones in the environment101 may each be playing different audio content. For instance, a usermay be grilling on the patio 101 i and listening to hip hop music beingplayed by the playback device 110 c while another user is preparing foodin the kitchen 101 h and listening to classical music played by theplayback device 110 b. In another example, a playback zone may play thesame audio content in synchrony with another playback zone. Forinstance, the user may be in the office 101 e listening to the playbackdevice 110 f playing back the same hip hop music being played back byplayback device 110 c on the patio 101 i. In some aspects, the playbackdevices 110 c and 110 f play back the hip hop music in synchrony suchthat the user perceives that the audio content is being playedseamlessly (or at least substantially seamlessly) while moving betweendifferent playback zones. Additional details regarding audio playbacksynchronization among playback devices and/or zones can be found, forexample, in U.S. Pat. No. 8,234,395 entitled, “System and method forsynchronizing operations among a plurality of independently clockeddigital data processing devices,” which is incorporated herein byreference in its entirety.

a. Suitable Media Playback System

FIG. 1B is a schematic diagram of the media playback system 100 and acloud network 102. For ease of illustration, certain devices of themedia playback system 100 and the cloud network 102 are omitted fromFIG. 1B. One or more communication links 103 (referred to hereinafter as“the links 103”) communicatively couple the media playback system 100and the cloud network 102.

The links 103 can comprise, for example, one or more wired networks, oneor more wireless networks, one or more wide area networks (WAN), one ormore local area networks (LAN), one or more personal area networks(PAN), one or more telecommunication networks (e.g., one or more GlobalSystem for Mobiles (GSM) networks, Code Division Multiple Access (CDMA)networks, Long-Term Evolution (LTE) networks, 5G communication networknetworks, and/or other suitable data transmission protocol networks),etc. The cloud network 102 is configured to deliver media content (e.g.,audio content, video content, photographs, social media content) to themedia playback system 100 in response to a request transmitted from themedia playback system 100 via the links 103. In some embodiments, thecloud network 102 is further configured to receive data (e.g. voiceinput data) from the media playback system 100 and correspondinglytransmit commands and/or media content to the media playback system 100.

The cloud network 102 comprises computing devices 106 (identifiedseparately as a first computing device 106 a, a second computing device106 b, and a third computing device 106 c). The computing devices 106can comprise individual computers or servers, such as, for example, amedia streaming service server storing audio and/or other media content,a voice service server, a social media server, a media playback systemcontrol server, etc. In some embodiments, one or more of the computingdevices 106 comprise modules of a single computer or server. In certainembodiments, one or more of the computing devices 106 comprise one ormore modules, computers, and/or servers. Moreover, while the cloudnetwork 102 is described above in the context of a single cloud network,in some embodiments the cloud network 102 comprises a plurality of cloudnetworks comprising communicatively coupled computing devices.Furthermore, while the cloud network 102 is shown in FIG. 1B as havingthree of the computing devices 106, in some embodiments, the cloudnetwork 102 comprises fewer (or more than) three computing devices 106.

The media playback system 100 is configured to receive media contentfrom the networks 102 via the links 103. The received media content cancomprise, for example, a Uniform Resource Identifier (URI) and/or aUniform Resource Locator (URL). For instance, in some examples, themedia playback system 100 can stream, download, or otherwise obtain datafrom a URI or a URL corresponding to the received media content. Anetwork 104 communicatively couples the links 103 and at least a portionof the devices (e.g., one or more of the playback devices 110, NMDs 120,and/or control devices 130) of the media playback system 100. Thenetwork 104 can include, for example, a wireless network (e.g., a WiFinetwork, a Bluetooth, a Z-Wave network, a ZigBee, and/or other suitablewireless communication protocol network) and/or a wired network (e.g., anetwork comprising Ethernet, Universal Serial Bus (USB), and/or anothersuitable wired communication). As those of ordinary skill in the artwill appreciate, as used herein, “WiFi” can refer to several differentcommunication protocols including, for example, Institute of Electricaland Electronics Engineers (IEEE) 802.11a, 802.11b, 802.11g, 802.11n,802.11ac, 802.11ac, 802.11ad, 802.11af, 802.11ah, 802.11ai, 802.11aj,802.11aq, 802.11ax, 802.11ay, 802.15, etc. transmitted at 2.4 Gigahertz(GHz), 5 GHz, and/or another suitable frequency.

In some embodiments, the network 104 comprises a dedicated communicationnetwork that the media playback system 100 uses to transmit messagesbetween individual devices and/or to transmit media content to and frommedia content sources (e.g., one or more of the computing devices 106).In certain embodiments, the network 104 is configured to be accessibleonly to devices in the media playback system 100, thereby reducinginterference and competition with other household devices. In otherembodiments, however, the network 104 comprises an existing householdcommunication network (e.g., a household WiFi network). In someembodiments, the links 103 and the network 104 comprise one or more ofthe same networks. In some aspects, for example, the links 103 and thenetwork 104 comprise a telecommunication network (e.g., an LTE network,a 5G network). Moreover, in some embodiments, the media playback system100 is implemented without the network 104, and devices comprising themedia playback system 100 can communicate with each other, for example,via one or more direct connections, PANs, telecommunication networks,and/or other suitable communication links.

In some embodiments, audio content sources may be regularly added orremoved from the media playback system 100. In some embodiments, forexample, the media playback system 100 performs an indexing of mediaitems when one or more media content sources are updated, added to,and/or removed from the media playback system 100. The media playbacksystem 100 can scan identifiable media items in some or all foldersand/or directories accessible to the playback devices 110, and generateor update a media content database comprising metadata (e.g., title,artist, album, track length) and other associated information (e.g.,URIs, URLs) for each identifiable media item found. In some embodiments,for example, the media content database is stored on one or more of theplayback devices 110, network microphone devices 120, and/or controldevices 130.

In the illustrated embodiment of FIG. 1B, the playback devices 110 l and110 m comprise a group 107 a. The playback devices 110 l and 110 m canbe positioned in different rooms in a household and be grouped togetherin the group 107 a on a temporary or permanent basis based on user inputreceived at the control device 130 a and/or another control device 130in the media playback system 100. When arranged in the group 107 a, theplayback devices 110 l and 110 m can be configured to play back the sameor similar audio content in synchrony from one or more audio contentsources. In certain embodiments, for example, the group 107 a comprisesa bonded zone in which the playback devices 110 l and 110 m compriseleft audio and right audio channels, respectively, of multi-channelaudio content, thereby producing or enhancing a stereo effect of theaudio content. In some embodiments, the group 107 a includes additionalplayback devices 110. In other embodiments, however, the media playbacksystem 100 omits the group 107 a and/or other grouped arrangements ofthe playback devices 110. Additional details regarding groups and otherarrangements of playback devices are described in further detail belowwith respect to FIGS. 1-I through IM.

The media playback system 100 includes the NMDs 120 a and 120 d, eachcomprising one or more microphones configured to receive voiceutterances from a user. In the illustrated embodiment of FIG. 1B, theNMD 120 a is a standalone device and the NMD 120 d is integrated intothe playback device 110 n. The NMD 120 a, for example, is configured toreceive voice input 121 from a user 123. In some embodiments, the NMD120 a transmits data associated with the received voice input 121 to avoice assistant service (VAS) configured to (i) process the receivedvoice input data and (ii) transmit a corresponding command to the mediaplayback system 100. In some aspects, for example, the computing device106 c comprises one or more modules and/or servers of a VAS (e.g., a VASoperated by one or more of SONOS®, AMAZON®, GOOGLE® APPLE®, MICROSOFT®).The computing device 106 c can receive the voice input data from the NMD120 a via the network 104 and the links 103. In response to receivingthe voice input data, the computing device 106 c processes the voiceinput data (i.e., “Play Hey Jude by The Beatles”), and determines thatthe processed voice input includes a command to play a song (e.g., “HeyJude”). The computing device 106 c accordingly transmits commands to themedia playback system 100 to play back “Hey Jude” by the Beatles from asuitable media service (e.g., via one or more of the computing devices106) on one or more of the playback devices 110.

b. Suitable Playback Devices

FIG. 1C is a block diagram of the playback device 110 a comprising aninput/output 111. The input/output 111 can include an analog I/O 111 a(e.g., one or more wires, cables, and/or other suitable communicationlinks configured to carry analog signals) and/or a digital I/O 111 b(e.g., one or more wires, cables, or other suitable communication linksconfigured to carry digital signals). In some embodiments, the analogI/O 111 a is an audio line-in input connection comprising, for example,an auto-detecting 3.5 mm audio line-in connection. In some embodiments,the digital I/O 111 b comprises a Sony/Philips Digital Interface Format(S/PDIF) communication interface and/or cable and/or a Toshiba Link(TOSLINK) cable. In some embodiments, the digital I/O 111 b comprises anHigh-Definition Multimedia Interface (HDMI) interface and/or cable. Insome embodiments, the digital I/O 111 b includes one or more wirelesscommunication links comprising, for example, a radio frequency (RF),infrared, WiFi, Bluetooth, or another suitable communication protocol.In certain embodiments, the analog I/O 111 a and the digital I/O 111 bcomprise interfaces (e.g., ports, plugs, jacks) configured to receiveconnectors of cables transmitting analog and digital signals,respectively, without necessarily including cables.

The playback device 110 a, for example, can receive media content (e.g.,audio content comprising music and/or other sounds) from a local audiosource 105 via the input/output 111 (e.g., a cable, a wire, a PAN, aBluetooth connection, an ad hoc wired or wireless communication network,and/or another suitable communication link). The local audio source 105can comprise, for example, a mobile device (e.g., a smartphone, atablet, a laptop computer) or another suitable audio component (e.g., atelevision, a desktop computer, an amplifier, a phonograph, a Blu-rayplayer, a memory storing digital media files). In some aspects, thelocal audio source 105 includes local music libraries on a smartphone, acomputer, a networked-attached storage (NAS), and/or another suitabledevice configured to store media files. In certain embodiments, one ormore of the playback devices 110, NMDs 120, and/or control devices 130comprise the local audio source 105. In other embodiments, however, themedia playback system omits the local audio source 105 altogether. Insome embodiments, the playback device 110 a does not include aninput/output 111 and receives all audio content via the network 104.

The playback device 110 a further comprises electronics 112, a userinterface 113 (e.g., one or more buttons, knobs, dials, touch-sensitivesurfaces, displays, touchscreens), and one or more transducers 114(referred to hereinafter as “the transducers 114”). The electronics 112is configured to receive audio from an audio source (e.g., the localaudio source 105) via the input/output 111, one or more of the computingdevices 106 a-c via the network 104 (FIG. 1B)), amplify the receivedaudio, and output the amplified audio for playback via one or more ofthe transducers 114. In some embodiments, the playback device 110 aoptionally includes one or more microphones 115 (e.g., a singlemicrophone, a plurality of microphones, a microphone array) (hereinafterreferred to as “the microphones 115”). In certain embodiments, forexample, the playback device 110 a having one or more of the optionalmicrophones 115 can operate as an NMD configured to receive voice inputfrom a user and correspondingly perform one or more operations based onthe received voice input.

In the illustrated embodiment of FIG. 1C, the electronics 112 compriseone or more processors 112 a (referred to hereinafter as “the processors112 a”), memory 112 b, software components 112 c, a network interface112 d, one or more audio processing components 112 g (referred tohereinafter as “the audio components 112 g”), one or more audioamplifiers 112 h (referred to hereinafter as “the amplifiers 112 h”),and power 112 i (e.g., one or more power supplies, power cables, powerreceptacles, batteries, induction coils, Power-over Ethernet (POE)interfaces, and/or other suitable sources of electric power). In someembodiments, the electronics 112 optionally include one or more othercomponents 112 j (e.g., one or more sensors, video displays,touchscreens, battery charging bases).

The processors 112 a can comprise clock-driven computing component(s)configured to process data, and the memory 112 b can comprise acomputer-readable medium (e.g., a tangible, non-transitorycomputer-readable medium, data storage loaded with one or more of thesoftware components 112 c) configured to store instructions forperforming various operations and/or functions. The processors 112 a areconfigured to execute the instructions stored on the memory 112 b toperform one or more of the operations. The operations can include, forexample, causing the playback device 110 a to retrieve audio data froman audio source (e.g., one or more of the computing devices 106 a-c(FIG. 1B)), and/or another one of the playback devices 110. In someembodiments, the operations further include causing the playback device110 a to send audio data to another one of the playback devices 110 aand/or another device (e.g., one of the NMDs 120). Certain embodimentsinclude operations causing the playback device 110 a to pair withanother of the one or more playback devices 110 to enable amulti-channel audio environment (e.g., a stereo pair, a bonded zone).

The processors 112 a can be further configured to perform operationscausing the playback device 110 a to synchronize playback of audiocontent with another of the one or more playback devices 110. As thoseof ordinary skill in the art will appreciate, during synchronousplayback of audio content on a plurality of playback devices, a listenerwill preferably be unable to perceive time-delay differences betweenplayback of the audio content by the playback device 110 a and the otherone or more other playback devices 110. Additional details regardingaudio playback synchronization among playback devices can be found, forexample, in U.S. Pat. No. 8,234,395, which was incorporated by referenceabove.

In some embodiments, the memory 112 b is further configured to storedata associated with the playback device 110 a, such as one or morezones and/or zone groups of which the playback device 110 a is a member,audio sources accessible to the playback device 110 a, and/or a playbackqueue that the playback device 110 a (and/or another of the one or moreplayback devices) can be associated with. The stored data can compriseone or more state variables that are periodically updated and used todescribe a state of the playback device 110 a. The memory 112 b can alsoinclude data associated with a state of one or more of the other devices(e.g., the playback devices 110, NMDs 120, control devices 130) of themedia playback system 100. In some aspects, for example, the state datais shared during predetermined intervals of time (e.g., every 5 seconds,every 10 seconds, every 60 seconds) among at least a portion of thedevices of the media playback system 100, so that one or more of thedevices have the most recent data associated with the media playbacksystem 100.

The network interface 112 d is configured to facilitate a transmissionof data between the playback device 110 a and one or more other deviceson a data network such as, for example, the links 103 and/or the network104 (FIG. 1B). The network interface 112 d is configured to transmit andreceive data corresponding to media content (e.g., audio content, videocontent, text, photographs) and other signals (e.g., non-transitorysignals) comprising digital packet data including an Internet Protocol(IP)-based source address and/or an IP-based destination address. Thenetwork interface 112 d can parse the digital packet data such that theelectronics 112 properly receives and processes the data destined forthe playback device 110 a.

In the illustrated embodiment of FIG. 1C, the network interface 112 dcomprises one or more wireless interfaces 112 e (referred to hereinafteras “the wireless interface 112 e”). The wireless interface 112 e (e.g.,a suitable interface comprising one or more antennae) can be configuredto wirelessly communicate with one or more other devices (e.g., one ormore of the other playback devices 110, NMDs 120, and/or control devices130) that are communicatively coupled to the network 104 (FIG. 1B) inaccordance with a suitable wireless communication protocol (e.g., WiFi,Bluetooth, LTE). In some embodiments, the network interface 112 doptionally includes a wired interface 112 f (e.g., an interface orreceptacle configured to receive a network cable such as an Ethernet, aUSB-A, USB-C, and/or Thunderbolt cable) configured to communicate over awired connection with other devices in accordance with a suitable wiredcommunication protocol. In certain embodiments, the network interface112 d includes the wired interface 112 f and excludes the wirelessinterface 112 e. In some embodiments, the electronics 112 excludes thenetwork interface 112 d altogether and transmits and receives mediacontent and/or other data via another communication path (e.g., theinput/output 111).

The audio processing components 112 g are configured to process and/orfilter data comprising media content received by the electronics 112(e.g., via the input/output 111 and/or the network interface 112 d) toproduce output audio signals. In some embodiments, the audio processingcomponents 112 g comprise, for example, one or more digital-to-analogconverters (DAC), audio preprocessing components, audio enhancementcomponents, a digital signal processors (DSPs), and/or other suitableaudio processing components, modules, circuits, etc. In certainembodiments, one or more of the audio processing components 112 g cancomprise one or more subcomponents of the processors 112 a. In someembodiments, the electronics 112 omits the audio processing components112 g. In some aspects, for example, the processors 112 a executeinstructions stored on the memory 112 b to perform audio processingoperations to produce the output audio signals.

The amplifiers 112 h are configured to receive and amplify the audiooutput signals produced by the audio processing components 112 g and/orthe processors 112 a. The amplifiers 112 h can comprise electronicdevices and/or components configured to amplify audio signals to levelssufficient for driving one or more of the transducers 114. In someembodiments, for example, the amplifiers 112 h include one or moreswitching or class-D power amplifiers. In other embodiments, however,the amplifiers include one or more other types of power amplifiers(e.g., linear gain power amplifiers, class-A amplifiers, class-Bamplifiers, class-AB amplifiers, class-C amplifiers, class-D amplifiers,class-E amplifiers, class-F amplifiers, class-G and/or class Hamplifiers, and/or another suitable type of power amplifier). In certainembodiments, the amplifiers 112 h comprise a suitable combination of twoor more of the foregoing types of power amplifiers. Moreover, in someembodiments, individual ones of the amplifiers 112 h correspond toindividual ones of the transducers 114. In other embodiments, however,the electronics 112 includes a single one of the amplifiers 112 hconfigured to output amplified audio signals to a plurality of thetransducers 114. In some other embodiments, the electronics 112 omitsthe amplifiers 112 h.

The transducers 114 (e.g., one or more speakers and/or speaker drivers)receive the amplified audio signals from the amplifier 112 h and renderor output the amplified audio signals as sound (e.g., audible soundwaves having a frequency between about 20 Hertz (Hz) and 20 kilohertz(kHz)). In some embodiments, the transducers 114 can comprise a singletransducer. In other embodiments, however, the transducers 114 comprisea plurality of audio transducers. In some embodiments, the transducers114 comprise more than one type of transducer. For example, thetransducers 114 can include one or more low frequency transducers (e.g.,subwoofers, woofers), mid-range frequency transducers (e.g., mid-rangetransducers, mid-woofers), and one or more high frequency transducers(e.g., one or more tweeters). As used herein, “low frequency” cangenerally refer to audible frequencies below about 500 Hz, “mid-rangefrequency” can generally refer to audible frequencies between about 500Hz and about 2 kHz, and “high frequency” can generally refer to audiblefrequencies above 2 kHz. In certain embodiments, however, one or more ofthe transducers 114 comprise transducers that do not adhere to theforegoing frequency ranges. For example, one of the transducers 114 maycomprise a mid-woofer transducer configured to output sound atfrequencies between about 200 Hz and about 5 kHz.

By way of illustration, SONOS, Inc. presently offers (or has offered)for sale certain playback devices including, for example, a “SONOS ONE,”“PLAY:1,” “PLAY:3,” “PLAY:5,” “PLAYBAR,” “PLAYBASE,” “CONNECT:AMP,”“CONNECT,” and “SUB.” Other suitable playback devices may additionallyor alternatively be used to implement the playback devices of exampleembodiments disclosed herein. Additionally, one of ordinary skilled inthe art will appreciate that a playback device is not limited to theexamples described herein or to SONOS product offerings. In someembodiments, for example, one or more playback devices 110 compriseswired or wireless headphones (e.g., over-the-ear headphones, on-earheadphones, in-ear earphones). In other embodiments, one or more of theplayback devices 110 comprise a docking station and/or an interfaceconfigured to interact with a docking station for personal mobile mediaplayback devices. In certain embodiments, a playback device may beintegral to another device or component such as a television, a lightingfixture, or some other device for indoor or outdoor use. In someembodiments, a playback device omits a user interface and/or one or moretransducers. For example, FIG. 1D is a block diagram of a playbackdevice 110 p comprising the input/output 111 and electronics 112 withoutthe user interface 113 or transducers 114.

FIG. 1E is a block diagram of a bonded playback device 110 q comprisingthe playback device 110 a (FIG. 1C) sonically bonded with the playbackdevice 110 i (e.g., a subwoofer) (FIG. 1A). In the illustratedembodiment, the playback devices 110 a and 110 i are separate ones ofthe playback devices 110 housed in separate enclosures. In someembodiments, however, the bonded playback device 110 q comprises asingle enclosure housing both the playback devices 110 a and 110 i. Thebonded playback device 110 q can be configured to process and reproducesound differently than an unbonded playback device (e.g., the playbackdevice 110 a of FIG. 1C) and/or paired or bonded playback devices (e.g.,the playback devices 110 l and 110 m of FIG. 1B). In some embodiments,for example, the playback device 110 a is full-range playback deviceconfigured to render low frequency, mid-range frequency, and highfrequency audio content, and the playback device 110 i is a subwooferconfigured to render low frequency audio content. In some aspects, theplayback device 110 a, when bonded with the first playback device, isconfigured to render only the mid-range and high frequency components ofa particular audio content, while the playback device 110 i renders thelow frequency component of the particular audio content. In someembodiments, the bonded playback device 110 q includes additionalplayback devices and/or another bonded playback device. Additionalplayback device embodiments are described in further detail below withrespect to FIGS. 2A-3D.

c. Suitable Network Microphone Devices (NMDs)

FIG. 1F is a block diagram of the NMD 120 a (FIGS. 1A and 1B). The NMD120 a includes one or more voice processing components 124 (hereinafter“the voice components 124”) and several components described withrespect to the playback device 110 a (FIG. 1C) including the processors112 a, the memory 112 b, and the microphones 115. The NMD 120 aoptionally comprises other components also included in the playbackdevice 110 a (FIG. 1C), such as the user interface 113 and/or thetransducers 114. In some embodiments, the NMD 120 a is configured as amedia playback device (e.g., one or more of the playback devices 110),and further includes, for example, one or more of the audio processingcomponents 112 g (FIG. 1C), the transducers 114, and/or other playbackdevice components. In certain embodiments, the NMD 120 a comprises anInternet of Things (IoT) device such as, for example, a thermostat,alarm panel, fire and/or smoke detector, etc. In some embodiments, theNMD 120 a comprises the microphones 115, the voice processing 124, andonly a portion of the components of the electronics 112 described abovewith respect to FIG. 1B. In some aspects, for example, the NMD 120 aincludes the processor 112 a and the memory 112 b (FIG. 1B), whileomitting one or more other components of the electronics 112. In someembodiments, the NMD 120 a includes additional components (e.g., one ormore sensors, cameras, thermometers, barometers, hygrometers).

In some embodiments, an NMD can be integrated into a playback device.FIG. 1G is a block diagram of a playback device 110 r comprising an NMD120 d. The playback device 110 r can comprise many or all of thecomponents of the playback device 110 a and further include themicrophones 115 and voice processing 124 (FIG. 1F). The playback device110 r optionally includes an integrated control device 130 c. Thecontrol device 130 c can comprise, for example, a user interface (e.g.,the user interface 113 of FIG. 1B) configured to receive user input(e.g., touch input, voice input) without a separate control device. Inother embodiments, however, the playback device 110 r receives commandsfrom another control device (e.g., the control device 130 a of FIG. 1B).Additional NMD embodiments are described in further detail below withrespect to FIGS. 3A-3F.

Referring again to FIG. 1F, the microphones 115 are configured toacquire, capture, and/or receive sound from an environment (e.g., theenvironment 101 of FIG. 1A) and/or a room in which the NMD 120 a ispositioned. The received sound can include, for example, vocalutterances, audio played back by the NMD 120 a and/or another playbackdevice, background voices, ambient sounds, etc. The microphones 115convert the received sound into electrical signals to produce microphonedata. The voice processing 124 receives and analyzes the microphone datato determine whether a voice input is present in the microphone data.The voice input can comprise, for example, an activation word followedby an utterance including a user request. As those of ordinary skill inthe art will appreciate, an activation word is a word or other audio cuethat signifying a user voice input. For instance, in querying theAMAZON® VAS, a user might speak the activation word “Alexa.” Otherexamples include “Ok, Google” for invoking the GOOGLE® VAS and “Hey,Siri” for invoking the APPLE® VAS.

After detecting the activation word, voice processing 124 monitors themicrophone data for an accompanying user request in the voice input. Theuser request may include, for example, a command to control athird-party device, such as a thermostat (e.g., NEST® thermostat), anillumination device (e.g., a PHILIPS HUE® lighting device), or a mediaplayback device (e.g., a Sonos® playback device). For example, a usermight speak the activation word “Alexa” followed by the utterance “setthe thermostat to 68 degrees” to set a temperature in a home (e.g., theenvironment 101 of FIG. 1A). The user might speak the same activationword followed by the utterance “turn on the living room” to turn onillumination devices in a living room area of the home. The user maysimilarly speak an activation word followed by a request to play aparticular song, an album, or a playlist of music on a playback devicein the home. Additional description regarding receiving and processingvoice input data can be found in further detail below with respect toFIGS. 3A-3F.

d. Suitable Control Devices

FIG. 1H is a partially schematic diagram of the control device 130 a(FIGS. 1A and 1B). As used herein, the term “control device” can be usedinterchangeably with “controller” or “control system.” Among otherfeatures, the control device 130 a is configured to receive user inputrelated to the media playback system 100 and, in response, cause one ormore devices in the media playback system 100 to perform an action(s) oroperation(s) corresponding to the user input. In the illustratedembodiment, the control device 130 a comprises a smartphone (e.g., aniPhone™, an Android phone) on which media playback system controllerapplication software is installed. In some embodiments, the controldevice 130 a comprises, for example, a tablet (e.g., an iPad™), acomputer (e.g., a laptop computer, a desktop computer), and/or anothersuitable device (e.g., a television, an automobile audio head unit, anIoT device). In certain embodiments, the control device 130 a comprisesa dedicated controller for the media playback system 100. In otherembodiments, as described above with respect to FIG. 1G, the controldevice 130 a is integrated into another device in the media playbacksystem 100 (e.g., one more of the playback devices 110, NMDs 120, and/orother suitable devices configured to communicate over a network).

The control device 130 a includes electronics 132, a user interface 133,one or more speakers 134, and one or more microphones 135. Theelectronics 132 comprise one or more processors 132 a (referred tohereinafter as “the processors 132 a”), a memory 132 b, softwarecomponents 132 c, and a network interface 132 d. The processor 132 a canbe configured to perform functions relevant to facilitating user access,control, and configuration of the media playback system 100. The memory132 b can comprise data storage that can be loaded with one or more ofthe software components executable by the processor 302 to perform thosefunctions. The software components 132 c can comprise applicationsand/or other executable software configured to facilitate control of themedia playback system 100. The memory 112 b can be configured to store,for example, the software components 132 c, media playback systemcontroller application software, and/or other data associated with themedia playback system 100 and the user.

The network interface 132 d is configured to facilitate networkcommunications between the control device 130 a and one or more otherdevices in the media playback system 100, and/or one or more remotedevices. In some embodiments, the network interface 132 d is configuredto operate according to one or more suitable communication industrystandards (e.g., infrared, radio, wired standards including IEEE 802.3,wireless standards including IEEE 802.11a, 802.11b, 802.11g, 802.11n,802.11ac, 802.15, 4G, LTE). The network interface 132 d can beconfigured, for example, to transmit data to and/or receive data fromthe playback devices 110, the NMDs 120, other ones of the controldevices 130, one of the computing devices 106 of FIG. 1B, devicescomprising one or more other media playback systems, etc. Thetransmitted and/or received data can include, for example, playbackdevice control commands, state variables, playback zone and/or zonegroup configurations. For instance, based on user input received at theuser interface 133, the network interface 132 d can transmit a playbackdevice control command (e.g., volume control, audio playback control,audio content selection) from the control device 304 to one or more ofplayback devices. The network interface 132 d can also transmit and/orreceive configuration changes such as, for example, adding/removing oneor more playback devices to/from a zone, adding/removing one or morezones to/from a zone group, forming a bonded or consolidated player,separating one or more playback devices from a bonded or consolidatedplayer, among others. Additional description of zones and groups can befound below with respect to FIGS. 1-I through 1M.

The user interface 133 is configured to receive user input and canfacilitate control of the media playback system 100. The user interface133 includes media content art 133 a (e.g., album art, lyrics, videos),a playback status indicator 133 b (e.g., an elapsed and/or remainingtime indicator), media content information region 133 c, a playbackcontrol region 133 d, and a zone indicator 133 e. The media contentinformation region 133 c can include a display of relevant information(e.g., title, artist, album, genre, release year) about media contentcurrently playing and/or media content in a queue or playlist. Theplayback control region 133 d can include selectable (e.g., via touchinput and/or via a cursor or another suitable selector) icons to causeone or more playback devices in a selected playback zone or zone groupto perform playback actions such as, for example, play or pause, fastforward, rewind, skip to next, skip to previous, enter/exit shufflemode, enter/exit repeat mode, enter/exit cross fade mode, etc. Theplayback control region 133 d may also include selectable icons tomodify equalization settings, playback volume, and/or other suitableplayback actions. In the illustrated embodiment, the user interface 133comprises a display presented on a touch screen interface of asmartphone (e.g., an iPhone™, an Android phone). In some embodiments,however, user interfaces of varying formats, styles, and interactivesequences may alternatively be implemented on one or more networkdevices to provide comparable control access to a media playback system.

The one or more speakers 134 (e.g., one or more transducers) can beconfigured to output sound to the user of the control device 130 a. Insome embodiments, the one or more speakers comprise individualtransducers configured to correspondingly output low frequencies,mid-range frequencies, and/or high frequencies. In some aspects, forexample, the control device 130 a is configured as a playback device(e.g., one of the playback devices 110). Similarly, in some embodimentsthe control device 130 a is configured as an NMD (e.g., one of the NMDs120), receiving voice commands and other sounds via the one or moremicrophones 135.

The one or more microphones 135 can comprise, for example, one or morecondenser microphones, electret condenser microphones, dynamicmicrophones, and/or other suitable types of microphones or transducers.In some embodiments, two or more of the microphones 135 are arranged tocapture location information of an audio source (e.g., voice, audiblesound) and/or configured to facilitate filtering of background noise.Moreover, in certain embodiments, the control device 130 a is configuredto operate as playback device and an NMD. In other embodiments, however,the control device 130 a omits the one or more speakers 134 and/or theone or more microphones 135. For instance, the control device 130 a maycomprise a device (e.g., a thermostat, an IoT device, a network device)comprising a portion of the electronics 132 and the user interface 133(e.g., a touch screen) without any speakers or microphones. Additionalcontrol device embodiments are described in further detail below withrespect to FIGS. 4A-4D and 5.

e. Suitable Playback Device Configurations

FIGS. 1-1 through 1M show example configurations of playback devices inzones and zone groups. Referring first to FIG. 1M, in one example, asingle playback device may belong to a zone. For example, the playbackdevice 110 g in the second bedroom 101 c (FIG. 1A) may belong to Zone C.In some implementations described below, multiple playback devices maybe “bonded” to form a “bonded pair” which together form a single zone.For example, the playback device 110 l (e.g., a left playback device)can be bonded to the playback device 110 l (e.g., a left playbackdevice) to form Zone A. Bonded playback devices may have differentplayback responsibilities (e.g., channel responsibilities). In anotherimplementation described below, multiple playback devices may be mergedto form a single zone. For example, the playback device 110 h (e.g., afront playback device) may be merged with the playback device 110 i(e.g., a subwoofer), and the playback devices 110 j and 110 k (e.g.,left and right surround speakers, respectively) to form a single Zone D.In another example, the playback devices 110 g and 110 h can be mergedto form a merged group or a zone group 108 b. The merged playbackdevices 110 g and 110 h may not be specifically assigned differentplayback responsibilities. That is, the merged playback devices 110 hand 110 i may, aside from playing audio content in synchrony, each playaudio content as they would if they were not merged.

Each zone in the media playback system 100 may be provided for controlas a single user interface (UI) entity. For example, Zone A may beprovided as a single entity named Master Bathroom. Zone B may beprovided as a single entity named Master Bedroom. Zone C may be providedas a single entity named Second Bedroom.

Playback devices that are bonded may have different playbackresponsibilities, such as responsibilities for certain audio channels.For example, as shown in FIG. 1-I, the playback devices 110 l and 110 mmay be bonded so as to produce or enhance a stereo effect of audiocontent. In this example, the playback device 110 l may be configured toplay a left channel audio component, while the playback device 110 k maybe configured to play a right channel audio component. In someimplementations, such stereo bonding may be referred to as “pairing.”

Additionally, bonded playback devices may have additional and/ordifferent respective speaker drivers. As shown in FIG. 1J, the playbackdevice 110 h named Front may be bonded with the playback device 110 inamed SUB. The Front device 110 h can be configured to render a range ofmid to high frequencies and the SUB device 110 i can be configuredrender low frequencies. When unbonded, however, the Front device 110 hcan be configured render a full range of frequencies. As anotherexample, FIG. 1K shows the Front and SUB devices 110 h and 110 i furtherbonded with Left and Right playback devices 110 j and 110 k,respectively. In some implementations, the Right and Left devices 110 jand 102 k can be configured to form surround or “satellite” channels ofa home theater system. The bonded playback devices 110 h, 110 i, 110 j,and 110 k may form a single Zone D (FIG. 1M).

Playback devices that are merged may not have assigned playbackresponsibilities, and may each render the full range of audio contentthe respective playback device is capable of. Nevertheless, mergeddevices may be represented as a single UI entity (i.e., a zone, asdiscussed above). For instance, the playback devices 110 a and 110 n themaster bathroom have the single UI entity of Zone A. In one embodiment,the playback devices 110 a and 110 n may each output the full range ofaudio content each respective playback devices 110 a and 110 n arecapable of, in synchrony.

In some embodiments, an NMD is bonded or merged with another device soas to form a zone. For example, the NMD 120 b may be bonded with theplayback device 110 e, which together form Zone F, named Living Room. Inother embodiments, a stand-alone network microphone device may be in azone by itself. In other embodiments, however, a stand-alone networkmicrophone device may not be associated with a zone. Additional detailsregarding associating network microphone devices and playback devices asdesignated or default devices may be found, for example, in previouslyreferenced U.S. patent application Ser. No. 15/438,749.

Zones of individual, bonded, and/or merged devices may be grouped toform a zone group. For example, referring to FIG. 1M, Zone A may begrouped with Zone B to form a zone group 108 a that includes the twozones. Similarly, Zone G may be grouped with Zone H to form the zonegroup 108 b. As another example, Zone A may be grouped with one or moreother Zones C-I. The Zones A-I may be grouped and ungrouped in numerousways. For example, three, four, five, or more (e.g., all) of the ZonesA-I may be grouped. When grouped, the zones of individual and/or bondedplayback devices may play back audio in synchrony with one another, asdescribed in previously referenced U.S. Pat. No. 8,234,395. Playbackdevices may be dynamically grouped and ungrouped to form new ordifferent groups that synchronously play back audio content.

In various implementations, the zones in an environment may be thedefault name of a zone within the group or a combination of the names ofthe zones within a zone group. For example, Zone Group 108 b can have beassigned a name such as “Dining+Kitchen”, as shown in FIG. 1M. In someembodiments, a zone group may be given a unique name selected by a user.

Certain data may be stored in a memory of a playback device (e.g., thememory 112 b of FIG. 1C) as one or more state variables that areperiodically updated and used to describe the state of a playback zone,the playback device(s), and/or a zone group associated therewith. Thememory may also include the data associated with the state of the otherdevices of the media system, and shared from time to time among thedevices so that one or more of the devices have the most recent dataassociated with the system.

In some embodiments, the memory may store instances of various variabletypes associated with the states. Variables instances may be stored withidentifiers (e.g., tags) corresponding to type. For example, certainidentifiers may be a first type “a1” to identify playback device(s) of azone, a second type “b1” to identify playback device(s) that may bebonded in the zone, and a third type “c1” to identify a zone group towhich the zone may belong. As a related example, identifiers associatedwith the second bedroom 101 c may indicate that the playback device isthe only playback device of the Zone C and not in a zone group.Identifiers associated with the Den may indicate that the Den is notgrouped with other zones but includes bonded playback devices 110 h-110k. Identifiers associated with the Dining Room may indicate that theDining Room is part of the Dining+Kitchen zone group 108 b and thatdevices 110 b and 110 d are grouped (FIG. 1L). Identifiers associatedwith the Kitchen may indicate the same or similar information by virtueof the Kitchen being part of the Dining+Kitchen zone group 108 b. Otherexample zone variables and identifiers are described below.

In yet another example, the media playback system 100 may variables oridentifiers representing other associations of zones and zone groups,such as identifiers associated with Areas, as shown in FIG. 1M. An areamay involve a cluster of zone groups and/or zones not within a zonegroup. For instance, FIG. 1M shows an Upper Area 109 a including ZonesA-D, and a Lower Area 109 b including Zones E-I. In one aspect, an Areamay be used to invoke a cluster of zone groups and/or zones that shareone or more zones and/or zone groups of another cluster. In anotheraspect, this differs from a zone group, which does not share a zone withanother zone group. Further examples of techniques for implementingAreas may be found, for example, in U.S. application Ser. No. 15/682,506filed Aug. 21, 2017 and titled “Room Association Based on Name,” andU.S. Pat. No. 8,483,853 filed Sep. 11, 2007, and titled “Controlling andmanipulating groupings in a multi-zone media system.” Each of theseapplications is incorporated herein by reference in its entirety. Insome embodiments, the media playback system 100 may not implement Areas,in which case the system may not store variables associated with Areas.

III. Example Systems and Devices

FIG. 2A is a front isometric view of a playback device 210 configured inaccordance with aspects of the disclosed technology. FIG. 2B is a frontisometric view of the playback device 210 without a grille 216 e. FIG.2C is an exploded view of the playback device 210. Referring to FIGS.2A-2C together, the playback device 210 comprises a housing 216 thatincludes an upper portion 216 a, a right or first side portion 216 b, alower portion 216 c, a left or second side portion 216 d, the grille 216e, and a rear portion 216 f. A plurality of fasteners 216 g (e.g., oneor more screws, rivets, clips) attaches a frame 216 h to the housing216. A cavity 216 j (FIG. 2C) in the housing 216 is configured toreceive the frame 216 h and electronics 212. The frame 216 h isconfigured to carry a plurality of transducers 214 (identifiedindividually in FIG. 2B as transducers 214 a-f). The electronics 212(e.g., the electronics 112 of FIG. 1C) is configured to receive audiocontent from an audio source and send electrical signals correspondingto the audio content to the transducers 214 for playback.

The transducers 214 are configured to receive the electrical signalsfrom the electronics 112, and further configured to convert the receivedelectrical signals into audible sound during playback. For instance, thetransducers 214 a-c (e.g., tweeters) can be configured to output highfrequency sound (e.g., sound waves having a frequency greater than about2 kHz). The transducers 214 d-f (e.g., mid-woofers, woofers, midrangespeakers) can be configured output sound at frequencies lower than thetransducers 214 a-c (e.g., sound waves having a frequency lower thanabout 2 kHz). In some embodiments, the playback device 210 includes anumber of transducers different than those illustrated in FIGS. 2A-2C.For example, as described in further detail below with respect to FIGS.3A-3C, the playback device 210 can include fewer than six transducers(e.g., one, two, three). In other embodiments, however, the playbackdevice 210 includes more than six transducers (e.g., nine, ten).Moreover, in some embodiments, all or a portion of the transducers 214are configured to operate as a phased array to desirably adjust (e.g.,narrow or widen) a radiation pattern of the transducers 214, therebyaltering a user's perception of the sound emitted from the playbackdevice 210.

In the illustrated embodiment of FIGS. 2A-2C, a filter 216 i is axiallyaligned with the transducer 214 b. The filter 216 i can be configured todesirably attenuate a predetermined range of frequencies that thetransducer 214 b outputs to improve sound quality and a perceived soundstage output collectively by the transducers 214. In some embodiments,however, the playback device 210 omits the filter 216 i. In otherembodiments, the playback device 210 includes one or more additionalfilters aligned with the transducers 214 b and/or at least another ofthe transducers 214.

FIGS. 3A and 3B are front and right isometric side views, respectively,of an NMD 320 configured in accordance with embodiments of the disclosedtechnology. FIG. 3C is an exploded view of the NMD 320. FIG. 3D is anenlarged view of a portion of FIG. 3B including a user interface 313 ofthe NMD 320. Referring first to FIGS. 3A-3C, the NMD 320 includes ahousing 316 comprising an upper portion 316 a, a lower portion 316 b andan intermediate portion 316 c (e.g., a grille). A plurality of ports,holes or apertures 316 d in the upper portion 316 a allow sound to passthrough to one or more microphones 315 (FIG. 3C) positioned within thehousing 316. The one or more microphones 316 are configured to receivedsound via the apertures 316 d and produce electrical signals based onthe received sound. In the illustrated embodiment, a frame 316 e (FIG.3C) of the housing 316 surrounds cavities 316 f and 316 g configured tohouse, respectively, a first transducer 314 a (e.g., a tweeter) and asecond transducer 314 b (e.g., a mid-woofer, a midrange speaker, awoofer). In other embodiments, however, the NMD 320 includes a singletransducer, or more than two (e.g., two, five, six) transducers. Incertain embodiments, the NMD 320 omits the transducers 314 a and 314 baltogether.

Electronics 312 (FIG. 3C) includes components configured to drive thetransducers 314 a and 314 b, and further configured to analyze audiodata corresponding to the electrical signals produced by the one or moremicrophones 315. In some embodiments, for example, the electronics 312comprises many or all of the components of the electronics 112 describedabove with respect to FIG. 1C. In certain embodiments, the electronics312 includes components described above with respect to FIG. 1F such as,for example, the one or more processors 112 a, the memory 112 b, thesoftware components 112 c, the network interface 112 d, etc. In someembodiments, the electronics 312 includes additional suitable components(e.g., proximity or other sensors).

Referring to FIG. 3D, the user interface 313 includes a plurality ofcontrol surfaces (e.g., buttons, knobs, capacitive surfaces) including afirst control surface 313 a (e.g., a previous control), a second controlsurface 313 b (e.g., a next control), and a third control surface 313 c(e.g., a play and/or pause control). A fourth control surface 313 d isconfigured to receive touch input corresponding to activation anddeactivation of the one or microphones 315. A first indicator 313 e(e.g., one or more light emitting diodes (LEDs) or another suitableilluminator) can be configured to illuminate only when the one or moremicrophones 315 are activated. A second indicator 313 f (e.g., one ormore LEDs) can be configured to remain solid during normal operation andto blink or otherwise change from solid to indicate a detection of voiceactivity. In some embodiments, the user interface 313 includesadditional or fewer control surfaces and illuminators. In oneembodiment, for example, the user interface 313 includes the firstindicator 313 e, omitting the second indicator 313 f. Moreover, incertain embodiments, the NMD 320 comprises a playback device and acontrol device, and the user interface 313 comprises the user interfaceof the control device.

Referring to FIGS. 3A-3D together, the NMD 320 is configured to receivevoice commands from one or more adjacent users via the one or moremicrophones 315. As described above with respect to FIG. 1B, the one ormore microphones 315 can acquire, capture, or record sound in a vicinity(e.g., a region within 10 m or less of the NMD 320) and transmitelectrical signals corresponding to the recorded sound to theelectronics 312. The electronics 312 can process the electrical signalsand can analyze the resulting audio data to determine a presence of oneor more voice commands (e.g., one or more activation words). In someembodiments, for example, after detection of one or more suitable voicecommands, the NMD 320 is configured to transmit a portion of therecorded audio data to another device and/or a remote server (e.g., oneor more of the computing devices 106 of FIG. 1B) for further analysis.The remote server can analyze the audio data, determine an appropriateaction based on the voice command, and transmit a message to the NMD 320to perform the appropriate action. For instance, a user may speak“Sonos, play Michael Jackson.” The NMD 320 can, via the one or moremicrophones 315, record the user's voice utterance, determine thepresence of a voice command, and transmit the audio data having thevoice command to a remote server (e.g., one or more of the remotecomputing devices 106 of FIG. 1B, one or more servers of a VAS and/oranother suitable service). The remote server can analyze the audio dataand determine an action corresponding to the command. The remote servercan then transmit a command to the NMD 320 to perform the determinedaction (e.g., play back audio content related to Michael Jackson). TheNMD 320 can receive the command and play back the audio content relatedto Michael Jackson from a media content source. As described above withrespect to FIG. 1B, suitable content sources can include a device orstorage communicatively coupled to the NMD 320 via a LAN (e.g., thenetwork 104 of FIG. 1B), a remote server (e.g., one or more of theremote computing devices 106 of FIG. 1B), etc. In certain embodiments,however, the NMD 320 determines and/or performs one or more actionscorresponding to the one or more voice commands without intervention orinvolvement of an external device, computer, or server.

FIG. 3E is a functional block diagram showing additional features of theNMD 320 in accordance with aspects of the disclosure. The NMD 320includes components configured to facilitate voice command captureincluding voice activity detector component(s) 312 k, beam formercomponents 312 l, acoustic echo cancellation (AEC) and/or self-soundsuppression components 312 m, activation word detector components 312 n,and voice/speech conversion components 312 o (e.g., voice-to-text andtext-to-voice). In the illustrated embodiment of FIG. 3E, the foregoingcomponents 312 k-312 o are shown as separate components. In someembodiments, however, one or more of the components 312 k-312 o aresubcomponents of the processors 112 a.

The beamforming and self-sound suppression components 312 l and 312 mare configured to detect an audio signal and determine aspects of voiceinput represented in the detected audio signal, such as the direction,amplitude, frequency spectrum, etc. The voice activity detector activitycomponents 312 k are operably coupled with the beamforming and AECcomponents 312 l and 312 m and are configured to determine a directionand/or directions from which voice activity is likely to have occurredin the detected audio signal. Potential speech directions can beidentified by monitoring metrics which distinguish speech from othersounds. Such metrics can include, for example, energy within the speechband relative to background noise and entropy within the speech band,which is measure of spectral structure. As those of ordinary skill inthe art will appreciate, speech typically has a lower entropy than mostcommon background noise.

The activation word detector components 312 n are configured to monitorand analyze received audio to determine if any activation words (e.g.,wake words) are present in the received audio. The activation worddetector components 312 n may analyze the received audio using anactivation word detection algorithm. If the activation word detector 312n detects an activation word, the NMD 320 may process voice inputcontained in the received audio. Example activation word detectionalgorithms accept audio as input and provide an indication of whether anactivation word is present in the audio. Many first- and third-partyactivation word detection algorithms are known and commerciallyavailable. For instance, operators of a voice service may make theiralgorithm available for use in third-party devices. Alternatively, analgorithm may be trained to detect certain activation words. In someembodiments, the activation word detector 312 n runs multiple activationword detection algorithms on the received audio simultaneously (orsubstantially simultaneously). As noted above, different voice services(e.g. AMAZON's ALEXA®, APPLE's SIRI®, or MICROSOFT's CORTANA®) can eachuse a different activation word for invoking their respective voiceservice. To support multiple services, the activation word detector 312n may run the received audio through the activation word detectionalgorithm for each supported voice service in parallel.

The speech/text conversion components 312 o may facilitate processing byconverting speech in the voice input to text. In some embodiments, theelectronics 312 can include voice recognition software that is trainedto a particular user or a particular set of users associated with ahousehold. Such voice recognition software may implementvoice-processing algorithms that are tuned to specific voice profile(s).Tuning to specific voice profiles may require less computationallyintensive algorithms than traditional voice activity services, whichtypically sample from a broad base of users and diverse requests thatare not targeted to media playback systems.

FIG. 3F is a schematic diagram of an example voice input 328 captured bythe NMD 320 in accordance with aspects of the disclosure. The voiceinput 328 can include a activation word portion 328 a and a voiceutterance portion 328 b. In some embodiments, the activation word 557 acan be a known activation word, such as “Alexa,” which is associatedwith AMAZON's ALEXA®. In other embodiments, however, the voice input 328may not include a activation word. In some embodiments, a networkmicrophone device may output an audible and/or visible response upondetection of the activation word portion 328 a. In addition oralternately, an NMB may output an audible and/or visible response afterprocessing a voice input and/or a series of voice inputs.

The voice utterance portion 328 b may include, for example, one or morespoken commands (identified individually as a first command 328 c and asecond command 328 e) and one or more spoken keywords (identifiedindividually as a first keyword 328 d and a second keyword 328 f). Inone example, the first command 328 c can be a command to play music,such as a specific song, album, playlist, etc. In this example, thekeywords may be one or words identifying one or more zones in which themusic is to be played, such as the Living Room and the Dining Room shownin FIG. 1A. In some examples, the voice utterance portion 328 b caninclude other information, such as detected pauses (e.g., periods ofnon-speech) between words spoken by a user, as shown in FIG. 3F. Thepauses may demarcate the locations of separate commands, keywords, orother information spoke by the user within the voice utterance portion328 b.

In some embodiments, the media playback system 100 is configured totemporarily reduce the volume of audio content that it is playing whiledetecting the activation word portion 557 a. The media playback system100 may restore the volume after processing the voice input 328, asshown in FIG. 3F. Such a process can be referred to as ducking, examplesof which are disclosed in U.S. patent application Ser. No. 15/438,749,incorporated by reference herein in its entirety.

FIGS. 4A-4D are schematic diagrams of a control device 430 (e.g., thecontrol device 130 a of FIG. 1H, a smartphone, a tablet, a dedicatedcontrol device, an IoT device, and/or another suitable device) showingcorresponding user interface displays in various states of operation. Afirst user interface display 431 a (FIG. 4A) includes a display name 433a (i.e., “Rooms”). A selected group region 433 b displays audio contentinformation (e.g., artist name, track name, album art) of audio contentplayed back in the selected group and/or zone. Group regions 433 c and433 d display corresponding group and/or zone name, and audio contentinformation audio content played back or next in a playback queue of therespective group or zone. An audio content region 433 e includesinformation related to audio content in the selected group and/or zone(i.e., the group and/or zone indicated in the selected group region 433b). A lower display region 433 f is configured to receive touch input todisplay one or more other user interface displays. For example, if auser selects “Browse” in the lower display region 433 f, the controldevice 430 can be configured to output a second user interface display431 b (FIG. 4B) comprising a plurality of music services 433 g (e.g.,Spotify, Radio by Tunein, Apple Music, Pandora, Amazon, TV, local music,line-in) through which the user can browse and from which the user canselect media content for play back via one or more playback devices(e.g., one of the playback devices 110 of FIG. 1A). Alternatively, ifthe user selects “My Sonos” in the lower display region 433 f, thecontrol device 430 can be configured to output a third user interfacedisplay 431 c (FIG. 4C). A first media content region 433 h can includegraphical representations (e.g., album art) corresponding to individualalbums, stations, or playlists. A second media content region 433 i caninclude graphical representations (e.g., album art) corresponding toindividual songs, tracks, or other media content. If the user selectionsa graphical representation 433 j (FIG. 4C), the control device 430 canbe configured to begin play back of audio content corresponding to thegraphical representation 433 j and output a fourth user interfacedisplay 431 d fourth user interface display 431 d includes an enlargedversion of the graphical representation 433 j, media content information433 k (e.g., track name, artist, album), transport controls 433 m (e.g.,play, previous, next, pause, volume), and indication 433 n of thecurrently selected group and/or zone name.

FIG. 5 is a schematic diagram of a control device 530 (e.g., a laptopcomputer, a desktop computer). The control device 530 includestransducers 534, a microphone 535, and a camera 536. A user interface531 includes a transport control region 533 a, a playback status region533 b, a playback zone region 533 c, a playback queue region 533 d, anda media content source region 533 e. The transport control regioncomprises one or more controls for controlling media playback including,for example, volume, previous, play/pause, next, repeat, shuffle, trackposition, crossfade, equalization, etc. The audio content source region533 e includes a listing of one or more media content sources from whicha user can select media items for play back and/or adding to a playbackqueue.

The playback zone region 533 b can include representations of playbackzones within the media playback system 100 (FIGS. 1A and 1B). In someembodiments, the graphical representations of playback zones may beselectable to bring up additional selectable icons to manage orconfigure the playback zones in the media playback system, such as acreation of bonded zones, creation of zone groups, separation of zonegroups, renaming of zone groups, etc. In the illustrated embodiment, a“group” icon is provided within each of the graphical representations ofplayback zones. The “group” icon provided within a graphicalrepresentation of a particular zone may be selectable to bring upoptions to select one or more other zones in the media playback systemto be grouped with the particular zone. Once grouped, playback devicesin the zones that have been grouped with the particular zone can beconfigured to play audio content in synchrony with the playbackdevice(s) in the particular zone. Analogously, a “group” icon may beprovided within a graphical representation of a zone group. In theillustrated embodiment, the “group” icon may be selectable to bring upoptions to deselect one or more zones in the zone group to be removedfrom the zone group. In some embodiments, the control device 530includes other interactions and implementations for grouping andungrouping zones via the user interface 531. In certain embodiments, therepresentations of playback zones in the playback zone region 533 b canbe dynamically updated as playback zone or zone group configurations aremodified.

The playback status region 533 c includes graphical representations ofaudio content that is presently being played, previously played, orscheduled to play next in the selected playback zone or zone group. Theselected playback zone or zone group may be visually distinguished onthe user interface, such as within the playback zone region 533 b and/orthe playback queue region 533 d. The graphical representations mayinclude track title, artist name, album name, album year, track length,and other relevant information that may be useful for the user to knowwhen controlling the media playback system 100 via the user interface531.

The playback queue region 533 d includes graphical representations ofaudio content in a playback queue associated with the selected playbackzone or zone group. In some embodiments, each playback zone or zonegroup may be associated with a playback queue containing informationcorresponding to zero or more audio items for playback by the playbackzone or zone group. For instance, each audio item in the playback queuemay comprise a uniform resource identifier (URI), a uniform resourcelocator (URL) or some other identifier that may be used by a playbackdevice in the playback zone or zone group to find and/or retrieve theaudio item from a local audio content source or a networked audiocontent source, possibly for playback by the playback device. In someembodiments, for example, a playlist can be added to a playback queue,in which information corresponding to each audio item in the playlistmay be added to the playback queue. In some embodiments, audio items ina playback queue may be saved as a playlist. In certain embodiments, aplayback queue may be empty, or populated but “not in use” when theplayback zone or zone group is playing continuously streaming audiocontent, such as Internet radio that may continue to play untilotherwise stopped, rather than discrete audio items that have playbackdurations. In some embodiments, a playback queue can include Internetradio and/or other streaming audio content items and be “in use” whenthe playback zone or zone group is playing those items.

When playback zones or zone groups are “grouped” or “ungrouped,”playback queues associated with the affected playback zones or zonegroups may be cleared or re-associated. For example, if a first playbackzone including a first playback queue is grouped with a second playbackzone including a second playback queue, the established zone group mayhave an associated playback queue that is initially empty, that containsaudio items from the first playback queue (such as if the secondplayback zone was added to the first playback zone), that contains audioitems from the second playback queue (such as if the first playback zonewas added to the second playback zone), or a combination of audio itemsfrom both the first and second playback queues. Subsequently, if theestablished zone group is ungrouped, the resulting first playback zonemay be re-associated with the previous first playback queue, or beassociated with a new playback queue that is empty or contains audioitems from the playback queue associated with the established zone groupbefore the established zone group was ungrouped. Similarly, theresulting second playback zone may be re-associated with the previoussecond playback queue, or be associated with a new playback queue thatis empty, or contains audio items from the playback queue associatedwith the established zone group before the established zone group wasungrouped.

FIG. 6 is a message flow diagram illustrating data exchanges betweendevices of the media playback system 100 (FIGS. 1A-1M).

At step 650 a, the media playback system 100 receives an indication ofselected media content (e.g., one or more songs, albums, playlists,podcasts, videos, stations) via the control device 130 a. The selectedmedia content can comprise, for example, media items stored locally onor more devices (e.g., the audio source 105 of FIG. 1C) connected to themedia playback system and/or media items stored on one or more mediaservice servers (one or more of the remote computing devices 106 of FIG.1B). In response to receiving the indication of the selected mediacontent, the control device 130 a transmits a message 651 a to theplayback device 110 a (FIGS. 1A-1C) to add the selected media content toa playback queue on the playback device 110 a.

At step 650 b, the playback device 110 a receives the message 651 a andadds the selected media content to the playback queue for play back.

At step 650 c, the control device 130 a receives input corresponding toa command to play back the selected media content. In response toreceiving the input corresponding to the command to play back theselected media content, the control device 130 a transmits a message 651b to the playback device 110 a causing the playback device 110 a to playback the selected media content. In response to receiving the message651 b, the playback device 110 a transmits a message 651 c to the firstcomputing device 106 a requesting the selected media content. The firstcomputing device 106 a, in response to receiving the message 651 c,transmits a message 651 d comprising data (e.g., audio data, video data,a URL, a URI) corresponding to the requested media content.

At step 650 d, the playback device 110 a receives the message 651 d withthe data corresponding to the requested media content and plays back theassociated media content.

At step 650 e, the playback device 110 a optionally causes one or moreother devices to play back the selected media content. In one example,the playback device 110 a is one of a bonded zone of two or more players(FIG. 1M). The playback device 110 a can receive the selected mediacontent and transmit all or a portion of the media content to otherdevices in the bonded zone. In another example, the playback device 110a is a coordinator of a group and is configured to transmit and receivetiming information from one or more other devices in the group. Theother one or more devices in the group can receive the selected mediacontent from the first computing device 106 a, and begin playback of theselected media content in response to a message from the playback device110 a such that all of the devices in the group play back the selectedmedia content in synchrony.

IV. Overview of Example Embodiments

As mentioned above, wireless surround sound systems are desirable formany reasons, including their ease of deployment, use,reconfigurability, and upgradeability. However, technical challengesarise when implementing wireless surround sound systems having more than5-7 surround sound channels played more than about 3 satellite playbackdevices.

The systems and methods disclosed and described herein overcome thetechnical challenges that can arise with wireless multi-channel surroundsound systems. In some embodiments, the systems and methods includeassigning channel streams to satellite playback devices, delayinginitial transmission of surround sound content to satellite playbackdevices to accumulate more audio samples for transmission of individualframes of surround sound content to satellite playback devices, andtaking advantage of configured playback delays for different channels ofsurround sound content to prioritize transmission of channels ofsurround sound content having shorter playback delays to some satelliteplayback devices over transmission of channels of surround sound contenthaving longer playback delays to other satellite playback devices.

V. Technical Features

In some embodiments, at least some aspects of the technical solutionsderive from the technical structure and organization of the channelstreams (and subchannels thereof), surround sound audio information,playback timing, and clock timing information that the soundbar andsatellite playback devices use to play surround sound audio informationtransmitted/received via channel streams in synchrony with each other,including how a soundbar (or other device equipped with a surround soundprocessor) generates playback timing for surround sound audioinformation based on clock timing, and how satellite playback devicesplay surround sound audio information in synchrony with the soundbar andthe other satellite playback devices based on playback timing and clocktiming.

Therefore, to aid in understanding certain aspects of the disclosedtechnical solutions, certain technical details of the channel streams,surround sound audio information, playback timing, and clock timinginformation, as well the generation and use of playback timing and clocktiming for playing surround sound audio information are described below.Except where noted, the technical details of the channel streams,surround sound audio information, playback timing, and clock timinginformation described below are the same or at least substantially thesame for the examples shown and described with reference to FIGS. 7, 8,and 9.

a. Surround Sound Content

Surround sound content may be any type of surround sound content nowknown or later developed. In some embodiments, the surround sound audiocontent comprises surround sound content associated with video content.However, not all surround sound content is necessarily associated withvideo content. For example, some audio-only surround sound content mayinclude movie soundtracks (without video), live concert recordings,immersive audio tracks, or similar content that may have been recordedfor reproduction via a surround sound system but yet not havecorresponding video content associated therewith.

In some embodiments, a surround sound processor for the surround soundsystem receives surround sound content from a surround sound contentsource, processes the surround sound content to generate a plurality ofchannel streams (described further herein) comprising portions of thesurround sound content (e.g., referred to as surround sound audioinformation, or audio samples of surround sound audio information), andtransmits the channel streams comprising the surround sound audioinformation to one or more satellite playback devices over a Local AreaNetwork (LAN), as described further herein.

In some embodiments, the surround sound processor is a standalonesurround sound controller comprising one or more processors, one or morenetwork and/or other interfaces, and tangible, non-transitorycomputer-readable media storing program code executed by the one or moreprocessors to cause the surround sound controller to perform thesurround sound processing features and functions described herein. Insome embodiments, the surround sound controller or processor is acomponent of a playback device within the multi-channel surround soundsystem. For example, the surround sound processor in some embodimentsmay be a component of a soundbar, entertainment head-end, television,audio tuner, computer, or other device comprising one or moreprocessors, one or more network and/or other interfaces, and tangible,non-transitory computer-readable media storing program code executed bythe one or more processors to cause the surround sound processor toperform the features and functions described herein.

In some embodiments, the surround sound content received by the surroundsound processor comprises multiple discrete surround sound channels,where each discrete surround sound channel is intended for playback byone or more predetermined speakers in a set of speakers in the surroundsound system, e.g., left front, right front, center, sub, left rear,right rear, etc. in a Dolby® Pro Logic® 5.1, 7.1, 9.1, 11.1 or otherchannel-based surround sound format. In some embodiments, the surroundsound content received by the surround sound processor comprisessurround sound content and surround sound audio object data, e.g., in aDolby Atmos® format, DTS:X® format, or other audio object-based format.In some embodiments that use audio object data (or similar data) likeDolby Atmos®, DTS:X®, and similar formats, the surround sound processorcomponent uses the audio object data and the surround sound content torender multiple channel streams comprising portions of the surroundsound content (based on the configuration of the surround sound system),and then provides the rendered channel streams to one or more playbackdevices (e.g., a soundbar and one or more satellite playback devices)for playback.

In some embodiments, the surround sound processor receives surroundsound content from a surround sound content source in digital form,e.g., as a stream of packets. In some embodiments, individual packets inthe stream of packets have a sequence number or other identifier thatspecifies an ordering of the packets. Packets transmitted over a datapacket network (e.g., Ethernet, WiFi, or other packet networks) mayarrive out of order, so the surround sound processor uses the sequencenumber or other identifier to reassemble the stream of packets in thecorrect order before performing further processing of the surround soundcontent. In some embodiments, the sequence number or other identifierthat specifies the ordering of the packets is or at least comprises atimestamp indicating a time when the packet was created by a device thattransmitted the packet. The packet creation time can be used as asequence number based on an assumption that packets are created in theorder in which they should be subsequently processed to create channelstreams.

After obtaining the surround sound content from the surround soundcontent source and processing the surround sound content to generatechannel streams comprising surround sound audio information as describedherein, the surround sound processor (or the playback device comprisingthe surround sound processor) in some embodiments (i) plays at least aportion of the processed surround sound content and/or (ii) transmits atleast a portion of the processed surround sound content to one or moreother playback devices.

b. Surround Sound Content Source

In operation, the surround sound processor component obtains any of theaforementioned types of surround sound content from a surround soundcontent source via an interface, e.g., a wired or wireless networkinterface(s), a “line-in” analog interface, a digital audio interface,an HDMI interface, an optical interface, or any other interface suitablefor receiving audio content in digital or analog format now known orlater developed.

A surround sound content source is any system, device, or applicationthat generates, provides, or otherwise makes available any of theaforementioned surround sound content to a surround sound processor. Forexample, in some embodiments, a surround sound content source includesany one or more of a streaming media (audio, video) service, digitalmedia server or other computing system, VAS service, gaming console,television, cable set-top-box, streaming media player (e.g., AppleTV,Roku, gaming console), CD/DVD player, telephone, tablet, or any othersource of surround sound content now known or later developed.

c. Channel Streams

In some embodiments, the surround sound processor (i) generates channelstreams based on the surround sound content and (ii) transmits one ormore of the generated channel streams (or at least one or more portionsthereof) to one or more playback devices in the multi-channel surroundsound system as described in further detail herein. As illustrated inFIG. 7, in some embodiments, a soundbar comprising the surround soundprocessor (i) generates channel streams based on the surround soundcontent and (ii) transmits one or more of the generated channel streams(or at least one or more portions thereof) to individual satelliteplayback devices in the surround sound system.

In operation, each channel stream includes surround sound audioinformation based on at least a portion of the surround sound contentreceived by the surround sound processor. In some embodiments, eachchannel stream may additionally include playback timing for the surroundsound audio information in the channel stream. In some embodiments, thesurround sound processor generates the playback timing for the surroundsound audio information in each channel stream. In some embodiments,individual channel streams comprise two or more subchannels of surroundsound audio information. For example, a channel stream for a playbackdevice may include left and right subchannels. In another example, achannel stream for a playback device may include subchannels forforward-firing and up-firing audio content.

In some embodiments, an individual channel stream includes both (i) thesurround sound audio information for the channel stream and (ii) theplayback timing for the surround sound audio information of the channelstream. For some embodiments where a channel stream includes multiplesubchannels, each subchannel includes audio information for thesubchannel and playback timing for the audio information of thesubchannel. But for some embodiments where a channel stream includesmultiple subchannels, each subchannel includes audio information for thesubchannel, but the channel stream includes playback timing for the setof subchannels, e.g., when a playback device is configured to play audioinformation from multiple subchannels at the same time.

Alternatively, in some embodiments, an individual channel streamincludes the surround sound audio information for the channel stream,and the playback timing for the surround sound audio information for thechannel stream is sent separately from the surround sound audioinformation of the channel stream.

In some embodiments, an individual channel stream includes a pluralityof frames (or cells, or packets), wherein an individual frame includes aportion (e.g., a set of audio samples) of surround sound audioinformation and a playback time for that portion of the surround soundaudio information (e.g., a playback time for that set of audio samples).In some embodiments, and as described further herein, the playback timefor that portion of the surround sound audio information corresponds toa future time relative to a clock time of a clock the surround soundprocessor uses to generate the playback timing for that portion of thesurround sound audio information.

In some embodiments, the soundbar (or other component comprising thesurround sound processor) transmits individual channel streams toindividual satellite playback devices using each satellite playbackdevice's individual network address. For example, in some embodiments,each satellite playback device has a corresponding unicast networkaddress, and the soundbar transmits each individual channel stream tothe channel stream's corresponding satellite playback device via thatsatellite playback device's corresponding unicast network address. Eachsatellite playback device receives its corresponding channel stream viaits corresponding unicast network address.

In some embodiments, the soundbar (or other component comprising thesurround sound processor) alternatively transmits one or more of thechannel streams to one or more of the satellite playback devices using amulticast network address, and one or more satellite playback devices inthe surround sound system receive the channel stream via that multicastaddress.

For example, in some embodiments, the soundbar transmits all of thechannel streams to a multicast network address, and all of the satelliteplayback devices receive all of the channel streams via the multicastnetwork address. Then, at each satellite playback device, the satelliteplayback device determines which channel stream(s) it should process togenerate analog audio signals for playback.

In another example, the soundbar transmits a first set of two or morechannel streams to a first multicast address, a second set of two ormore channel streams to a second multicast address, and so on. And afirst set of two or more satellite playback devices receives the firstset of two or more channel streams via the first multicast address, anda second set of two or more satellite playback devices receives thesecond set of two or more channel streams via the second multicastaddress. Then, at each satellite playback device in the first set of twoor more satellite playback devices, the satellite playback devicedetermines which channel stream(s) it should process to generate analogaudio signals for playback. And at each satellite playback device in thesecond set of two or more satellite playback devices, the satelliteplayback device determines which channel stream(s) it should process togenerate analog audio signals for playback.

d. Playback Timing

Playback devices (including the soundbar and the satellite playbackdevices) disclosed and described herein use playback timing for surroundsound audio information in a channel stream to generate and playbackanalog audio signals based on surround sound audio information in thechannel stream. In some embodiments, the soundbar (or other componentcomprising a surround sound processor) generates the playback timing forthe surround sound audio information for each channel stream based onclock timing (described below).

In some embodiments, the soundbar (i) generates playback timing forsurround sound audio information of an individual channel stream basedon clock timing from a local clock at the soundbar, and (ii) transmitsthe generated playback timing to all other playback devices configuredto receive the individual channel stream and play the surround soundaudio information in that individual channel stream.

In operation, when generating playback timing for an individual frame(or packet) of a channel stream (or subchannel thereof), the soundbaradds a “timing advance” to the current clock time of a local referenceclock of the soundbar. Adding this “timing advance” to the current clocktime results in a playback time for the frame/packet (or frames/packets)that amounts to a future time relative to that current clock time of thesoundbar at the time the soundbar generated the frame(s)/packet(s)comprising the portion(s) of the surround sound audio information.

In some embodiments, the “timing advance” is based on an amount of timethat is greater than or equal to the sum of (i) the network transit timerequired for frames and/or packets of the channel stream comprising thesurround sound audio information transmitted from the soundbar to arriveat the satellite playback device(s) configured to use the playbacktiming for playing the surround sound audio information in that channelstream and (ii) the amount of time required for the satellite playbackdevice(s) configured to use that playback timing to receive, process,and play the surround sound audio information in that channel stream.

In some embodiments, the soundbar determines a timing advance by sendingone or more test packets to one or more (or perhaps all) satelliteplayback devices configured to play surround sound content, and thenreceiving test response packets back from the satellite playbackdevices. In some embodiments, the soundbar and the one or more satelliteplayback devices negotiate a timing advance via multiple test andresponse messages. In some embodiments with two or more satelliteplayback devices, the soundbar determines a timing advance by exchangingtest and response messages with all of the satellite playback devices,and then setting a timing advance that is sufficient for the satelliteplayback device having the longest total of network transmit time andpacket processing time.

In some embodiments, the timing advance is less than about 15-20milliseconds. In further embodiments, the timing advance is less thanabout 10 milliseconds. In some embodiments, the timing advance remainsconstant after being determined, or at least remains constant for asubstantial duration, e.g., during an entire surround sound playbacksession. In other embodiments, the soundbar can change the timingadvance (including changing the timing advance during a surround soundplayback session) in response to a request from a satellite playbackdevice indicating that a greater timing advance is required (e.g.,because the satellite playback device is not receiving packets of itschannel stream comprising portions of surround sound audio content untilafter other satellite playback devices have already played correspondingportions of the surround sound content) or a shorter timing advancewould be sufficient (e.g., because the satellite playback device isbuffering more packets of its channel stream comprising portions ofsurround sound audio information than necessary to provide consistent,reliable playback).

In some embodiments, the playback timing is generated for individualframes (or packets), or individual sets of frames or packets, comprisingaudio samples of the surround sound audio information of a channelstream. As described above, in some embodiments, the surround soundaudio information is packaged in a series of frames (or packets) whereindividual frames (or packets) comprise a portion of the surround soundaudio information, e.g., audio samples of the surround sound audioinformation. In some embodiments, the playback timing for the surroundsound audio information includes a playback time for each frame (orpacket) of the surround sound audio information. In some embodiments,the playback timing for an individual frame is included within the frame(or packet), e.g., in the header of the frame, in an extended header ofthe frame, in the payload portion of the frame, and/or in some otherdesignated portion of the frame. In other embodiments, the playbacktiming for a set of frames (or packets) is included within one frame ofthe set of frames, or alternatively, the playback timing for the set offrames is included in a separate frame associated with the correspondingset of frames.

In some embodiments, the playback time for an individual frame (orpacket) is identified within a timestamp or other indication. In suchembodiments, the timestamp (or other indication) represents a time toplay the surround sound audio information within that individual frame(or packet), or perhaps groups/sets of frames or packets. In operation,when the playback timing for an individual frame (or packet) isgenerated, the playback timing for that individual frame is a futuretime relative to a current clock time of a reference clock at the timethat the playback timing for that individual frame is generated.

e. Clock Timing

Clock timing can play an important role in synchronous playback of thesurround sound content disclosed and described herein. In operation, thesoundbar uses its own local clock and playback timing for surround soundaudio information in a channel stream to generate and play analog audiosignals based on the surround sound audio information in that channelstream. And each satellite playback device in the surround sound systemuses clock timing information from the soundbar, the satellite playbackdevice's local clock timing, and the playback timing for surround soundaudio information in a channel stream to generate and play analog audiosignals based on the surround sound audio information received in thechannel stream.

To facilitate synchronous playback of the surround sound content by allthe devices in the surround sound system, the soundbar (or other devicecomprising the surround sound processor) provides clock timinginformation to the satellite playback devices. This clock timinginformation includes a clock time of the reference clock that thesoundbar uses to generate playback timing for surround sound audioinformation in an individual channel stream.

In some embodiments, each satellite playback device receives one or morechannel streams comprising surround sound audio information and playbacktiming information for the surround sound audio information in thechannel stream. The surround sound audio information and the playbacktiming for the surround sound audio information in each channel streamis unique to each channel stream. However, the soundbar generates theplayback timing for each channel stream using the same reference clock.So, while each satellite playback device receives surround sound audioinformation and playback timing (for that surround sound audioinformation) unique to its channel stream(s), all the satellite playbackdevices receive the same clock timing information from the soundbar (orother device comprising the surround sound processor).

f. The Soundbar Using Playback Timing and Clock Timing to Play SurroundSound Content in Synchrony with Other Satellite Playback Devices

As mentioned earlier, in some embodiments, the surround sound processoris a component of a soundbar that is configured to play one or more ofthe channel streams (or subchannels thereof) generated by the surroundsound processor. In such embodiments, the soundbar uses its local clocktiming to generate playback timing for the surround sound audioinformation in each channel stream that the surround sound processorgenerates (based on the surround sound content). In operation, thesoundbar (i) plays one or more of the generated channel streams and (ii)transmits one or more other channel streams to the satellite playbackdevice(s). Recall from above that the surround sound audio informationin each channel stream has associated playback timing, and that theplayback device tasked with playing the surround sound audio content forthat channel stream (whether it's a soundbar or a satellite playbackdevice) uses the playback timing to play the surround sound audioinformation of that channel stream.

For each channel stream that the soundbar is configured to play, thesoundbar uses the previously-generated playback timing for the surroundsound audio information of the channel stream and its locally-generatedclock timing to generate and play analog audio signals based on thesurround sound audio information of the channel stream. In operation,the soundbar plays an individual frame (or packet) comprising portions(e.g., audio samples) of the surround sound audio content when thesoundbar's local clock that the soundbar used to generate the playbacktiming reaches the time specified in the playback timing for thatindividual frame (or packet).

For example, recall that when generating playback timing for anindividual frame (or packet), the soundbar device adds a “timingadvance” to the current clock time of the reference clock that thesoundbar uses for generating the playback timing and for playing thesurround sound audio information. So, if the timing advance for anindividual frame is, for example, 15 milliseconds, then the soundbarplays the portion (e.g., a sample or set of samples) of surround soundaudio content in an individual frame (or packet) 15 milliseconds aftercreating the playback timing for that individual frame (or packet).

By playing the portion(s) of the surround sound audio content of anindividual frame and/or packet when the clock time of the localreference clock at the soundbar reaches the playback timing for thatindividual frame or packet, the soundbar plays that portion(s) of theaudio content in that individual frame/packet in synchrony with thesatellite playback devices.

g. Satellite Playback Devices Using Playback Timing and Clock Timing toPlay Surround Sound Content in Synchrony with the Soundbar and OtherSatellite Playback Devices

Recall that, in some embodiments, the soundbar (or other devicecomprising the surround sound processor) transmits channel streamscomprising surround sound audio information along with playback timingfor the surround sound audio information to the satellite playbackdevices. The soundbar (or other device comprising the surround soundprocessor) also transmits clock timing information to the satelliteplayback devices. And while each satellite playback device receivessurround sound audio information and playback timing (for that surroundsound audio information) that is unique to its channel stream(s), allthe satellite playback devices receive the same clock timing informationfrom the soundbar (or other device comprising the surround soundprocessor).

To play an individual frame (or packet) of surround sound audioinformation in synchrony with the soundbar and the other satelliteplayback device(s), the satellite playback device, for each channelstream that the satellite playback device is configured to process, (i)receives the frames (or packets) of the channel stream comprising theportions of the surround sound audio information from the soundbar, (ii)receives the playback timing for the surround sound audio informationfrom the soundbar (e.g., in the frame and/or packet headers of theframes and/or packets of the channel stream comprising the portions ofthe surround sound audio information or perhaps separately from theframes and/or packets of the channel stream comprising the portions ofthe surround sound audio information), (iii) receives the clock timingfrom the soundbar, and (iv) plays the portion(s) of the surround soundaudio information in the individual frame (or packet) when the satelliteplayback device's local clock that the satellite playback device usesfor playback reaches the playback time specified in the playback timingfor that individual frame (or packet) of surround sound audioinformation received from the soundbar, as adjusted by a “timingoffset.”

In operation, after the satellite playback device receives clock timingfrom the soundbar (or other device comprising the surround soundprocessor), the satellite playback device determines a “timing offset”for the satellite playback device. This “timing offset” comprises (or atleast corresponds to) a difference between the “reference” clock at thesoundbar (that the soundbar used to generate the playback timing) and a“local” clock at the satellite playback device that the satelliteplayback device uses to play the surround sound content. In operation,each satellite playback device that receives the clock timing from thesoundbar calculates its own “timing offset” based on the differencebetween its local clock and the clock timing received from the soundbar,and thus, the “timing offset” that each satellite playback determines isspecific to that particular satellite playback device. As such, each ofthe satellite playback devices may operate with different timingoffsets.

In some embodiments, when playing back the surround sound audioinformation of a particular channel stream, the satellite playbackdevice generates new playback timing (specific to the satellite playbackdevice) for individual frames (or packets) of surround sound audioinformation by adding the previously determined “timing offset” to theplayback timing for each frame (or packet) of surround sound audioinformation of the channel stream received from the soundbar. With thisapproach, the satellite playback device converts the playback timing forthe surround sound audio information received from the soundbar into“local” playback timing for the satellite playback device. Because eachsatellite playback device calculates its own “timing offset,” eachsatellite playback device's determined “local” playback timing for anindividual frame is specific to that particular satellite playbackdevice.

And when the “local” clock that the satellite playback device is usingfor playing back the surround sound audio information received via thechannel stream reaches the “local” playback time for an individual frame(or packet) comprising portions (e.g., audio samples) of the surroundsound audio information, the satellite playback device plays theportions of surround sound audio information (e.g., the audio samples ofsurround sound information) associated with that individual frame (orpacket).

Thus, each satellite playback device plays frames (or packets)comprising portions of the surround sound audio information of itsassigned channel stream(s) according to the playback timing for thatsurround sound audio information as adjusted by the “timing offset”based on a difference between the satellite playback device's clocktiming and the soundbar's clock timing. And because the soundbargenerated the playback timing for those frames (or packets) of surroundsound audio information for each satellite playback device's assignedchannel stream(s) relative to the soundbar's local clock timing, andfurther, because the soundbar uses that same local clock timing to playcorresponding frames (or packets) of surround sound audio information ofthe channel stream(s) assigned to the soundbar, each satellite playbackdevice and the soundbar play their corresponding frames (or packets)comprising corresponding portions of surround sound audio informationfor the same surround sound content in synchrony, i.e., at the same timeor at substantially the same time, even when none of the soundbar orplayback devices are synchronized to a master clock.

VI. Example Wireless Surround Sound System Architecture

FIG. 7 shows an example configuration of a multichannel surround soundsystem 700 according to some embodiments.

The multichannel surround sound system 700 comprises a plurality ofplayback devices, including a Soundbar 702, a Sub₁ 710, a Sub₂ 712, anOverhead 714, a Rear L 716, and a Rear R 718. In operation, theplurality of playback devices 702, 710-718 are configured to communicatewith each other directly and/or indirectly via a Local Area Network(LAN) 720. In some embodiments, the Soundbar 702, Sub₁ 710, Sub₂ 712,Overhead 714, Rear L 716, and Rear R 718 playback devices are connectedto the LAN 720, and the Soundbar 702 communicates directly with thesatellite playback devices (i.e., the Sub₁ 710, Sub₂ 712, Overhead 714,Rear L 716, and Rear R 718 playback devices) via direct wirelesstransmissions so that packets and/or frames transmitted between andamong the Soundbar 702, Sub₁ 710, Sub₂ 712, Overhead 714, Rear L 716,and Rear R 718 playback devices need not traverse a WiFi router or LANaccess point. In other embodiments, packets and/or frames transmittedbetween and among the Soundbar 702, Sub₁ 710, Sub₂ 712, Overhead 714,Rear L 716, and Rear R 718 playback devices traverse an intermediateWiFi router or LAN access point as in a typical WiFi LAN configuration.In some embodiments, some packets/frames transmitted directly betweenand among the Soundbar 702, Sub₁ 710, Sub₂ 712, Overhead 714, Rear L716, and Rear R 718 playback devices without traversing a WiFi router oraccess point, and some packets/frames transmitted indirectly (e.g.,traverse a WiFi router or access point) between and among the Soundbar702, Sub₁ 710, Sub₂ 712, Overhead 714, Rear L 716, and Rear R 718playback devices. For example, in some embodiments, the Soundbar 702 maytransmit channel streams (and perhaps other transmissions associatedwith synchronous playback, such as clock timing and/or playback timing)to individual satellite playback devices (i.e., the Sub₁ 710, Sub₂ 712,Overhead 714, Rear L 716, and Rear R 718 playback devices) via directwireless transmissions that do not traverse a WiFi router or accesspoint, but the Soundbar 702 may transmit packets/frames comprising otherdata (e.g., other management and control signaling and messages) to theindividual satellite playback devices via transmissions that traversethe WiFi router or access point.

The Soundbar 702 is configured to play (i) a front left channel (FL) viaFront L speaker 704, (ii) a front right channel (FR) via Front R speaker706, and (iii) a front center channel (FC) via Front Center speaker 708.Collectively, the set of FL, FR, and FC channels are sometimes referredto herein as the front channels, or F channels. In some embodiments, theSoundbar 702 is additionally configured to play certain overheadchannels via upward-firing speaker drivers, such as a front rightup-firing channel (FRU), a front left up-firing channel (FLU), and acenter up-firing channel (FCU). In some such embodiments, the front (F)channels include the set of FL, FLU, FR, FRU, FC, and FCU channels.

In some embodiments, Soundbar 702 includes a surround sound processorconfigured to perform the surround sound processor functions disclosedand described herein. In some embodiments, the Soundbar 702 isconsidered a surround sound system controller and the playback devicesSub₁ 710, Sub₂ 712, Overhead 714, Rear L 716, and Rear R 718 areconsidered surround sound satellites or satellite playback devices.

The Sub₁ 710 is configured to play a first sub channel (S1). Sub₁ 710 issimilar to or the same as any of the subwoofer playback devicesdisclosed herein, including but not limited to subwoofer 110 i (FIG. 1)and Sub₂ 712.

The Sub₂ 712 is configured to play a second sub channel (S2). Sub₂ 712is similar to or the same as any of the subwoofer playback devicesdisclosed herein, including but not limited to subwoofer 110 i (FIG. 1)and Sub₁ 710.

The Overhead 714 is configured to play one or more overhead channels(OH). In example surround sound system 700, Overhead 714 comprises anetworked multi-channel amplifier configured to play multiple overheadchannels via speaker drivers installed in a ceiling. For example, insome embodiments, Overhead 714 is configured to play an Overhead Right(OH-R) and an Overhead Left (OH-L) channel. In some embodiments,Overhead 714 is alternatively configured to play an Center OverheadRight (COH-R), a Center Overhead Left (COH-L), a Rear Overhead Right(RO-R), and a Rear Overhead Left (RO-L) channel. In some embodiments,the set of channels comprising two or more of OH-R, OH-L, COH-R, COH-L,RO-R, and RO-L that are played by Overhead 714 are referred to as the OHchannels. In other embodiments, Overhead 714 may alternatively comprisea playback device with one or more upward-firing speaker drivers. Insome embodiments, overhead 714 comprises one or more in-ceiling playbackdevices. In some embodiments, Overhead 714 is the same or similar to anyof the playback devices disclosed herein.

Rear L 716 is configured to play a Rear Left channel (RL). In someembodiments, Rear L 716 is additionally configured to play a Rear LeftUp-firing (RL-U) channel, e.g., via upward-firing speaker drivers. Insome such embodiments, the set of channels comprising one or more of RLand/or RL-U that are played by Rear L 716 are referred to as the RLchannels. Rear L 716 is similar to or the same as any of the playbackdevices disclosed herein.

Rear R 718 is configured to play a Rear Right channel (RR). In someembodiments, Rear R 718 is additionally configured to play a Rear RightUp-firing (RR-U) channel, e.g., via upward-firing speaker drivers. Insome such embodiments, the set of channels comprising one or more of RRand/or RR-U that are played by Rear R 718 are referred to as the RRchannels. Rear R 718 is similar to or the same as any of the playbackdevices disclosed herein.

Some embodiments may additionally include one or more of headphones 722a and 722 b for listening to surround sound content when the otherplayback devices in the system 700 are muted.

In operation, in the example system 700, Soundbar 702 receives surroundsound content from a surround sound content source and processes thesurround sound content as described herein to generate a plurality ofchannel streams. Each channel stream includes surround sound audioinformation for playback by a playback device (e.g., the Soundbar 702and the satellite playback devices 710-718). The Soundbar 702 then playsone or more of the generated channel streams and transmits othergenerated channel streams to Sub₁ 710, Sub₂ 712, Overhead 714, Rear L716, and Rear R 718 for playback. The individual channel streams (orsubchannels thereof) correspond to individual channels of surround soundaudio to be played by playback devices in the surround sound system 700.

VII. Example Timing Diagram

FIG. 8 shows an example timing diagram 800 for generating andtransmitting surround sound audio information to satellite playbackdevices for a multichannel surround sound system according to someembodiments. Persons of skill in the art will appreciate that the sizeof the frames (or sets of frames) of the channel streams shown indiagram 800 do not necessarily correspond to specific amounts of data,number of audio samples, frame/packet size, transmission duration, orother physical attributes relating to the packaging, transmission, orplayback of the surround sound audio information.

With reference to the example system architecture 700 in FIG. 7, timingdiagram 800 illustrates one example implementation of how Soundbar 702generates a plurality of channel streams 802-814, plays the surroundsound audio information of channel stream 802, and transmits the channelstreams 804-814 to the satellite playback devices for playback,including Sub₁ 710, Sub₂ 712, Overhead 714, Rear L 716, and Rear R 718.

More particularly, region 816 of the timing diagram 800 shows thegeneration of channel streams 802-814 as function of a plurality ofmulti-millisecond timeframes illustrated along the x-axis of the diagram800, region 818 of the timing diagram 800 shows the transmission ofchannel streams 804-814 as a function of the plurality ofmulti-millisecond timeframes, and region 820 of the timing diagram 800shows playback of channel streams 802-814 as a function of the pluralityof multi-millisecond timeframes.

The example procedures illustrated in example timing diagram 800 satisfytwo important technical requirements for enabling the surround soundsystem 700 to play surround sound content having corresponding videocontent, e.g., video content for a television show, movie, video game,web video, or other video content. First, for surround sound contentthat has corresponding video content, it can be important for theSoundbar 702 to process and distribute the surround sound content to thesatellite playback devices 710-718 for processing and playback insynchrony with the Soundbar 702 sufficiently quickly such that thesurround sound content collectively played by the surround sound system700 is not perceived to be out of sync with the corresponding videocontent. Second, in addition to playing the surround sound content insync with (or at least substantially in sync with) its correspondingvideo content, the Soundbar 702 and the satellite playback devices710-718 also play their respective portions of the surround soundcontent in synchrony with each other so that the surround sound contentdoes not have undesirable echo effects caused by playback delays amongand between the Soundbar 702 and the satellite playback devices 710-718.In some embodiments, playing the surround sound content “substantiallyin sync” with its corresponding video content refers to playing thesurround sound content within a threshold range of timeframes before orafter the corresponding video content is displayed on a screen (e.g.,playing the surround sound content between about −180 ms and about +80ms of displaying the corresponding video content, playing the surroundsound content between about −130 ms and about +50 ms of displaying thecorresponding video content, and/or playing the surround sound contentbetween about −100 ms and +25 ms of displaying the corresponding videocontent).

In some embodiments, to ensure that the surround sound system 700 playsthe surround sound content in sync with (or at least substantially insync with) corresponding video content, the Soundbar 702 is configuredplay audio information for the front channels (e.g., FL, FR, and FCchannels) within about 29 ms after receiving the surround sound content.This approximately 29 ms delay from receipt to playback for the Soundbar702 serves as a reference point for the satellite playback devices710-718 and provides a period of time for the system 700 to generate,transmit, receive, and playback the surround sound content in synchronywith each other in sync with (or at least substantially in sync with)the corresponding video content.

In some embodiments, the Soundbar 702 may be configured to play theaudio information for the front channels sooner than about 29 ms afterreceiving the surround sound content, e.g., 25 ms, 20 ms, 18 ms, or someother shorter delay. But in some instances, using a shorter delay maycause some satellite playback devices to receive audio content after theaudio content's designated playback time, thereby resulting in audiodrop outs by the satellite playback device. Similarly, the Soundbar 702may be configured to play the audio information for the front channelslater than about 29 ms after receiving the surround sound content, e.g.,32 ms, 35 ms, 40 ms, or some other longer delay. But in some instances,using a longer delay may cause playback of the surround sound content tobe perceived to be out of sync with the corresponding video content.

a. Generating Channel Streams

The first function performed during the approximately 29 ms timeframeincludes the Soundbar 702 processing the incoming surround sound contentto generate a plurality of channel streams 802-814.

In some embodiments, processing the incoming surround sound contentincludes mixing channels of surround sound content to generateindividual channels of surround sound audio information for playback bythe Soundbar 702 and the satellite playback devices 710-718. In someembodiments, processing the incoming surround sound content includesusing audio object information (e.g., Dolby Atmos® or DTS:X® audioobject information) to generate a plurality of channels of surroundsound audio information for playback by the Soundbar 702 and thesatellite playback devices 710-718.

In operation, each of the channel streams 802-814 contains surroundsound audio information for playback by one of the playback devices inthe system 700. In some embodiments, one or more of the channel streamscomprise subchannels of surround sound audio information.

For example, in the illustrative embodiment shown in FIG. 8, the Fchannel stream 802 includes surround sound audio information to beplayed by the Soundbar 702. The surround sound audio information in theF channel stream 802 to be played by the Soundbar 702 includes 5subchannels, including (i) front left channel (FL) audio information forplayback via Front L speaker 704 of Soundbar 702, (ii) front rightchannel (FR) audio information for playback via Front R speaker 706 ofSoundbar 702, (iii) front center channel (FC) audio information forplayback via Front Center speaker 708 of Soundbar 702, (iv) front rightup-firing channel (FRU) audio information for playback via a front rightupward firing speaker driver (not shown), and (v) front left up-firingchannel (FLU) audio information for playback via a front left upwardfiring speaker driver (not shown).

The S1 channel stream 804 includes surround sound audio information tobe played by the Sub₁ 710 playback device. And the S2 channel stream 806includes surround sound audio information to be played by the Sub₂ 712playback device. In the example shown in FIG. 8, both of the S1 channelstream 804 and the S2 channel stream 806 have a single channel ofsurround sound audio information for each of the Sub₁ 710 and Sub₂ 712playback devices, respectively.

The OH channel stream 810 includes surround sound audio information tobe played by the Overhead 714 playback device. The surround sound audioinformation in the OH channel stream 810 to be played by the Overhead714 playback device includes 2 subchannels, including (i) overhead left(OH-L) audio information for playback via a left ceiling speaker (notshown), and (ii) overhead right (OH-R) audio information for playbackvia a left ceiling speaker (not shown).

The RL channel stream 812 includes surround sound audio information tobe played by the Rear L 716 playback device. The surround sound audioinformation in the RL channel stream 812 to be played by the Rear L 716playback device includes 2 subchannels, including (i) rear left forward(RL-F) audio information for playback via a forward-firing speakerdriver of the Rear L 716 playback device, and (ii) rear left upward(RL-U) audio information for playback via an upward-firing speakerdriver of the Rear L 716 playback device.

And the RR channel stream 814 includes surround sound audio informationto be played by the Rear R 718 playback device. The surround sound audioinformation in the RR channel stream 814 to be played by the Rear R 718playback device includes 2 subchannels, including (i) rear right forward(RR-F) audio information for playback via a forward-firing speakerdriver of the Rear R 718 playback device, and (ii) rear right upward(RR-U) audio information for playback via an upward-firing speakerdriver of the Rear R 718 playback device.

In some embodiments, generating the plurality of channel streams 802-814includes the Soundbar 702 generating, for each channel stream (or forchannel streams with multiple subchannels, generating for eachsubchannel of the channel stream), (i) a series of frames (or packets,cells, or similar) comprising the surround sound audio information forthe channel stream (or subchannel thereof), where each frame includes atleast a portion of the surround sound audio information of the channelstream (or subchannel thereof), and (ii) playback timing for thesurround sound audio information of the channel stream (or subchannelthereof).

In some embodiments, individual frames in the series of frames includeboth (i) a portion of the surround sound audio information and (ii)playback timing for that portion of the surround sound audio informationin the frame. In some embodiments, each frame in the series of framesincludes both (i) a portion of the surround sound audio information and(ii) playback timing for that portion of the surround sound audioinformation in the frame. As described previously, the playback timingfor an individual frame includes a future time, relative to the clocktime of the Soundbar 702, at which the surround sound audio informationin the frame is to be played by the playback device configured to playthat surround sound audio information.

In some embodiments of the example timing diagram 800, individualchannel streams (or subchannels thereof) comprise the above-describedplurality of frames comprising portions of surround sound audioinformation and playback timing for the surround sound audioinformation.

For example, the F channel stream 802 includes a plurality of framesrepresented as F₀-F₁₁, where each of F₀-F₁₁ represents 5 frames (becausethe F channel stream 802 has five subchannels in this exampleembodiment, i.e., FC, FL, FR, FLU, and FRU described above), and whereeach frame comprises a portion of the surround sound audio informationto be played by the Soundbar 702 and timing information for that portionof the surround sound audio information to be played by the Soundbar702. In some embodiments, rather than each frame having playback timing,the F channel stream 802 includes playback timing information for eachset of 5 frames that the Soundbar 702 is to play at the same time.

The S1 channel stream 804 includes a plurality of frames represented asS1₀-S1₁₁, where each of S1₀-S1₁₁ represents 1 frame (because the S1channel stream 804 does not have any subchannels in this exampleembodiment), and where each frame comprises a portion of the surroundsound audio information to be played by the Sub₁ 710 playback device andtiming information for that portion of the surround sound audioinformation to be played by the Sub₁ 710 playback device.

The S2 channel stream 806 includes a plurality of frames represented asS2₀-S2₁₁, where each of S2₀-S2₁₁ represents 1 frame (because the S2channel stream 806 does not have any subchannels in this exampleembodiment), and where each frame comprises a portion of the surroundsound audio information to be played by the Sub₂ 712 playback device andtiming information for that portion of the surround sound audioinformation to be played by the Sub₂ 712 playback device.

The OH channel stream 810 includes a plurality of frames represented asOH₀-OH₁₁, where each of OH₀-OH₁₁ represents 2 frames (because the OHchannel stream 810 has two subchannels in this example embodiment, i.e.,OH-L and OH-R described above), and where each frame comprises a portionof the surround sound audio information to be played by the Overhead 714playback device and timing information for that portion of the surroundsound audio information to be played by the Overhead 714 playbackdevice. In some embodiments, rather than each frame having playbacktiming, the OH channel stream 810 includes playback timing informationfor each set of 2 frames that the Overhead 714 playback device is toplay at the same time.

The RL channel stream 812 includes a plurality of frames represented asRL₀-RL₁₁, where each of RL₀-RL₁₁ represents 2 frames (because the RLchannel stream 812 includes two subchannels, i.e., RL-F and RL-U,described above), and where each frame comprises a portion of thesurround sound audio information to be played by the Rear L 716 playbackdevice and timing information for that portion of the surround soundaudio information to be played by the Rear L 716 playback device. Insome embodiments, rather than each frame having playback timing, the RLchannel stream 812 includes playback timing information for each set of2 frames that the Rear L 716 playback device is to play at the sametime.

And lastly, The RR channel stream 814 includes a plurality of framesrepresented as RR₀-RR₁₁, where each of RR₀-RR₁₁ represents 2 frames(because the RR channel stream 814 includes two subchannels, i.e., RR-Fand RR-U, described above), and where each frame comprises a portion ofthe surround sound audio information to be played by the Rear R 718playback device and timing information for that portion of the surroundsound audio information to be played by the Rear R 718 playback device.In some embodiments, rather than each frame having playback timing, theRR channel stream 814 includes playback timing information for each setof 2 frames that the Rear R 718 playback device is to play at the sametime.

Thus, in the example configuration of FIGS. 7 and 8, the surround soundsystem 700 comprises 13 channels. In particular, 5 front channels (FC,FL, FR, FLU, and FRU), 2 subwoofer channels (S1 and S2), 2 overheadchannels (OH-L and OH-R), 2 rear left channels (RL-F and RL-U), and 2rear right channels (RR-F and RR-U). In operation, the Soundbar 702plays the 5 front channels and transmits the 8 other channels to thesatellite playback devices via 5 channel streams. However, in otherembodiments, individual channel streams may have more or fewersubchannels (or perhaps no subchannels) than the example shown here.Additionally, other embodiments may have more or fewer channel streamsand/or more or fewer satellite playback devices.

Time-critical applications like distributing the multiple channelstreams 802-814 comprising surround sound audio information in areal-time or substantially real-time manner to the plurality ofsatellite playback devices 710-718 sufficiently quickly so that thesystem 700 as a whole can play the surround sound content in synchronywith each other and in sync with the corresponding video contentrequires striking a careful balance between frame size and correspondingframe transmission rates. Accordingly, the frame size of the frames tobe transmitted via each channel stream is an important consideration forthe transmission scheme. Here, frame size (or packet, cell, or similardata package size) refers to the number of audio samples in each frame.

Larger frame sizes (i.e., more audio samples per frame) can deliver moreaudio samples per frame to a satellite playback device, thereby reducingthe frequency at which the Soundbar 702 must transmit frames to thesatellite playback devices. And because each frame requires someoverhead (e.g., addressing, error checking, etc.), using larger framesizes has a better surround sound audio information to overhead ratiothan using smaller frame sizes because more of the transmissionbandwidth is used for surround sound audio information rather than frameoverhead. However, larger frame sizes take longer to transmit thansmaller frame sizes (i.e., fewer audio samples per frame), and becausethe LAN is a shared transmission medium and prone to collisions withtransmissions from other devices on the network and radio frequency (RF)interference, larger frame sizes are more prone to corruption duringtransmission by collisions and RF interference than smaller frame sizes,which in turn tends to increase the number of retransmissions requiredto deliver all the frames to all the satellite playback devices over thenetwork.

On the other hand, while using smaller frame sizes tends to reduce thenumber of retransmissions, using smaller frame sizes increases thefrequency at which the Soundbar 702 must transmit frames to thesatellite playback devices. Further, because, as explained previously,each frame requires some frame overhead (e.g., addressing, errorchecking, etc.), using a larger number of smaller-sized frames has alower surround sound audio information to overhead ratio than atransmission scheme that uses a smaller number of larger-sized frames.Thus, using a larger number of smaller-sized frames results in moresystem bandwidth being used to transmit frame overhead (rather thanactual surround sound audio information) as compared to using a smallernumber of larger-sized frames. Additionally, using a larger number ofsmaller-sized frames requires the Soundbar 702 to generate moreframes-per-millisecond and requires each satellite playback device toprocess more frames-per-millisecond as compared to using a smallernumber of larger-sized frames.

In some embodiments, each frame of the plurality of frames in eachchannel stream of the plurality channel streams 802-814 comprises 256samples of audio information, corresponding to 5.8 ms of audio at a 44.1kHz sample rate. Other frame sizes comprising more or fewer audiosamples corresponding to more or less audio content at higher or lowersample rates could be used, too, e.g., 128 samples or 512 samples. Insome embodiments, the size of frames (or packets) transmitted via somechannel streams may be larger or smaller than the size of frames (orpackets) transmitted via other channel streams.

In the example timing diagram 800, during timeframe ΔT_(x), Soundbar 702generates frame_(x), of each channel stream (or subchannel thereof) inthe plurality of channel streams 802-814. For example, during timeframeΔT₀, Soundbar 702 generates (i) the five frames F₀ of the F channelstream 802 (one frame for each of FC, FR, FL, FRU, and FLU), (ii) thesingle frame S1₀ of the S1 channel stream 804, (iii) the single frameS2₀ of the S2 channel stream 806, (iv) the two frames OH₀ of the OHchannel stream 810 (one frame for each of OH-L and OH-R), (v) the twoframes RL₀ of the RL channel stream 812 (one frame for each of RL-F andRL-U), and (vi) the two frames RR₀ of the RR channel stream 814 (oneframe for each of RR-F and RR-U).

Similarly, during timeframe ΔT₁, Soundbar 702 generates (i) the fiveframes F₁ of the F channel stream 802 (one frame for each of FC, FR, FL,FRU, and FLU), (ii) the single frame S1₁ of the S1 channel stream 804,(iii) the single frame S2₁ of the S2 channel stream 806, (iv) the twoframes OH₁ of the OH channel stream 810 (one frame for each of OH-L andOH-R), (v) the two frames RL₁ of the RL channel stream 812 (one framefor each of RL-F and RL-U), and (vi) the two frames RR₁ of the RRchannel stream 814 (one frame for each of RR-F and RR-U).

During timeframe ΔT₂, Soundbar 702 generates (i) the five frames F₂ ofthe F channel stream 802 (one frame for each of FC, FR, FL, FRU, andFLU), (ii) the single frame S1₂ of the S1 channel stream 804, (iii) thesingle frame S2₂ of the S2 channel stream 806, (iv) the two frames OH₂of the OH channel stream 810 (one frame for each of OH-L and OH-R), (v)the two frames RL₂ of the RL channel stream 812 (one frame for each ofRL-F and RL-U), and (vi) the two frames RR₂ of the RR channel stream 814(one frame for each of RR-F and RR-U).

During timeframe ΔT₃, Soundbar 702 generates (i) the five frames F₃ ofthe F channel stream 802 (one frame for each of FC, FR, FL, FRU, andFLU) (ii) the single frame S1₃ of the S1 channel stream 804, (iii) thesingle frame S2₃ of the S2 channel stream 806, (iv) the two frames OH₃of the OH channel stream 810 (one frame for each of OH-L and OH-R), (v)the two frames RL₃ of the RL channel stream 812 (one for each of RL-Fand RL-U), and (vi) the two frames RR₃ of the RR channel stream 814 (onefor each of RR-F and RR-U).

In operation, the Soundbar 702 continues to generate frames for each ofthe channel streams 802-814 in this manner until the Soundbar 702 ceasesto receive surround sound content from the surround sound source.

b. Transmitting Channel Streams

The second function performed during the approximately 29 ms timeframeincludes the Soundbar 702 transmitting channel streams 804-814 tocorresponding satellite playback devices 710-718 via the LAN 720. Region818 of timing diagram 800 shows the transmission of channel streams fromthe Soundbar 702 to the satellite playback devices 710-718.

In operation, to provide some aspects of the surround sound effect, someof the satellite playback devices 710-718 are configured to playportions of the surround sound audio information earlier or later thanother satellite playback devices, relative to playback of correspondingportions of the surround sound audio information by the Soundbar 702.

In the example timing diagram 800, the subwoofer playback devices (e.g.,Sub₁ 710 and Sub₂ 712) are configured to play their portions of thesurround sound audio information about 5 ms after the Soundbar 702 playsits same corresponding portion of the surround sound audio information,i.e., or about 34 ms after the Soundbar 702 has received and decoded theincoming surround sound content from the surround sound content source.And the other satellite playback devices (e.g., Overhead 714, Rear L716, and Rear R 718) are configured to play their respective portions ofthe surround sound audio information about 10 ms after the Soundbar 702plays its corresponding portion of the surround sound audio information,i.e., about 39 ms after the Soundbar 702 has received and decoded thesurround sound content from the surround sound content source. However,other example configurations could use different delay times relative tothe Soundbar 702 and/or different delay times for different satelliteplayback devices, depending on the number and configuration of playbackdevices in the surround sound system, and at least to some extent,aspects of the desired surround sound effect.

In some embodiments, Soundbar 702 incorporates the delay time for anindividual satellite playback device into the playback timinginformation for the surround sound audio information in the channelstream for that satellite playback device. In other embodiments, anindividual satellite playback device can incorporate its delay time byusing the delay time (e.g., 5-10 ms or some other amount of delay time)to adjust either (i) the “timing offset” between the satellite playbackdevice clock timing and the Soundbar 702 clock timing or (ii) the“local” playback timing that the satellite playback device determinesfor individual frames of the surround sound audio information receivedvia the channel stream assigned to the satellite playback device.

But to ensure that the satellite playback devices 710-718 receive theircorresponding portions of the surround sound audio information insufficient time for the satellite playback devices 710-718 to processand play their corresponding potions of the surround sound audioinformation at the appropriate playback time, and because the LAN 720 isa shared transmission medium, the Soundbar 702 prioritizes thetransmission of channel streams for satellite playback devices havingshorter delay times relative to the Soundbar 702 ahead of channelstreams for satellite playback devices having longer delay timesrelative to the Soundbar 702. Therefore, in the above-described examplewhere Sub₁ 710 and Sub₂ 712 are configured play their portions of thesurround sound content 5 ms after the Soundbar 702 plays itscorresponding portions of the surround sound content, and Overhead 714,Rear L 716, and Rear R 718 are configured to play their portions of thesurround sound content 10 ms after the Soundbar 702 plays itscorresponding portions, the Soundbar 702 prioritizes transmission of thechannel streams for the subwoofer playback devices ahead of the channelstreams for the overhead and rear playback devices.

In the example timing diagram 800, Soundbar 702 (i) during a first timeinterval, transmits a first set of frames of channel streams S1, S2, andOH, and (ii) during a second time interval following the first timeinterval, transmits a second set of frames of channels streams RL andRR.

For example, after a time delay of 2t to accumulate frames fortransmission, Soundbar 702 begins transmitting frames comprisingsurround sound audio information to the satellite playback devices710-718.

During timeframe ΔT₂, Soundbar 702 transmits (a) the S1₀ and S1₁ framesof the S1 channel stream 804 to Sub₁ 710, (b) the S2₀ and S2₁ frames ofthe S2 channel stream 806 to Sub₂ 712, and (c) the OH₀ and OH₁ frames ofthe OH channel stream 810 to Overhead 714.

During timeframe ΔT₃, Soundbar 702 transmits (a) the RL₁ and RL₂ framesof the RL channel stream 812 to Rear L 716, and (b) the RR₁ and RR₂frames of the RR channel stream 814 to Rear R 718.

During timeframe ΔT₄, Soundbar 702 transmits (a) the S1₂ and S1₃ framesof the S1 channel stream 804 to Sub₁ 710, (b) the S2₂ and S2₃ frames ofthe S2 channel stream 806 to Sub₂ 712, and (c) the OH₂ and OH₃ frames ofthe OH channel stream 810 to Overhead 714

During timeframe ΔT₅, Soundbar 702 transmits (a) the RL₃ and RL₄ framesof the RL channel stream 812 to Rear L 716, and (b) the RR₃ and RR₄frames of the RR channel stream 814 to Rear R 718.

During timeframe ΔT₆, Soundbar 702 transmits (a) the S1₄ and S1₅ framesof the S1 channel stream 804 to Sub₁ 710, (b) the S2₄ and S2₅ frames ofthe S2 channel stream 806 to Sub₂ 712, and (c) the OH₄ and OH₅ frames ofthe OH channel stream 810 to Overhead 714.

During timeframe ΔT₇, Soundbar 702 transmits (a) the RL₅ and RL₆ framesof the RL channel stream 812 to Rear L 716, and (b) the RR₅ and RR₆frames of the RR channel stream 814 to Rear R 718.

In operation, the Soundbar 702 continues to transmit frames for each ofthe channel streams 804-814 to their corresponding satellite playbackdevices 710-718 in this manner until the Soundbar 702 ceases to receivesurround sound content from the surround sound source.

The 2t delay between frame generation and frame transmission introducesan otherwise undesirable delay in the overall playback scheme because itreduces the amount of time available for the Soundbar 702 to transmitthe frames to the satellite playback devices and for the satelliteplayback devices to receive, process, and play the surround sound audioinformation within the frames as described herein. As mentioned above,one important requirement for playing surround sound content that hasassociated video content is that the surround sound system 700 play thesurround sound content in sync (or at least substantially in sync) withthe video content. Adding the additional 2t delay increases the riskthat playback of the surround sound content will not be sufficiently insync with presentation of the corresponding video content. However, inthis instance, the 2t delay enables the Soundbar 702 to accumulate moreaudio samples to transmit to each satellite playback device, therebyimproving the transmission efficiency of the system by transmitting moreaudio samples per frame.

Although the timing diagram 800 shows fairly even and consistenttransmission of frames (or sets of frames) from the Soundbar 702 to theindividual satellite playback devices 710-718, in practice, the actualtransmission times (and durations) may fluctuate within a particulartime interval, and some transmissions may even occur in a later intervalbecause of contentions when seizing the RF channel for transmission,collisions and backoffs, RF interference, retransmissions, processordelays, and/or other computing and/or network situations that may causeminor irregularities and/or inconsistencies in the transmission andreception of the frames between the Soundbar 702 and the satelliteplayback devices 710-718 via the LAN 720. In some embodiments, allowingfor extra time during every other time period as illustrated in example800 provides opportunities for the system 700 to catch up after minordelays in the transmission, reception, and/or playback of the audioinformation via the channel streams.

c. Playing Surround Sound Audio Content from Channel Streams

The third function performed during the approximately 29 ms timeframeincludes each satellite playback device 710-718 receiving itscorresponding channel stream 804-814 from the Soundbar 702 via the LAN720, processing the channel stream to extract the surround sound audioinformation from the channel stream, and then use the surround soundaudio information, the playback timing information, and clockinformation to play the surround sound audio information in synchronywith the Soundbar 702 and the other satellite playback devices of thesystem 700.

Region 820 of timing diagram 800 shows when the Soundbar 702 and theindividual satellite playback devices 710-718 play correspondingportions of the surround sound content. In operation, the Soundbar 702and the individual satellite playback devices 710-718 all play surroundsound audio information of their corresponding channel streams based onplayback timing and clock timing as described earlier in detail herein.

During timeframe ΔT₅, Soundbar 702 plays the surround sound audioinformation in the F₀ frames.

During ΔT₆, Soundbar 702 plays the surround sound audio information inthe F₁ frames.

During ΔT₇, Soundbar 702 plays the surround sound audio information inthe F₂ frames, the Sub₁ 710 playback device plays the surround soundaudio information in the S1₀ frames, and the Sub₂ 712 playback deviceplays the surround sound audio information in the S2₀ frames.

During ΔT₈, Soundbar 702 plays the surround sound audio information inthe F₃ frames, the Sub₁ 710 playback device plays the surround soundaudio information in the S1₁ frames, the Sub₂ 712 playback device playsthe surround sound audio information in the S2₁ frames, the Overhead 714playback device plays the surround sound audio information in the OH₀frames, the Rear L 716 playback device plays the surround sound audioinformation in the RL₀ frames, and the Rear R 718 playback device playsthe surround sound audio information in the RR₀ frames.

During ΔT₉, Soundbar 702 plays the surround sound audio information inthe F₄ frames, the Sub₁ 710 playback device plays the surround soundaudio information in the S1₂ frames, the Sub₂ 712 playback device playsthe surround sound audio information in the S2₂ frames, the Overhead 714playback device plays the surround sound audio information in the OH₁frames, the Rear L 716 playback device plays the surround sound audioinformation in the RL₁ frames, and the Rear R 718 playback device playsthe surround sound audio information in the RR₁ frames.

During ΔT₁₀, Soundbar 702 plays the surround sound audio information inthe F₅ frames, the Sub₁ 710 playback device plays the surround soundaudio information in the S1₃ frames, the Sub₂ 712 playback device playsthe surround sound audio information in the S2₃ frames, the Overhead 714playback device plays the surround sound audio information in the OH₂frames, the Rear L 716 playback device plays the surround sound audioinformation in the RL₂ frames, and the Rear R 718 playback device playsthe surround sound audio information in the RR₂ frames.

As shown in the timing diagram 800, the subwoofer playback devices (Sub₁710 and Sub₂ 712) play their portions of the surround sound audioinformation about 5 ms after the Soundbar 702 plays its samecorresponding portions of the surround sound audio information. And theother satellite playback devices (Overhead 714, Rear L 716, and Rear R718) play their respective portions of the surround sound audioinformation about 10 ms after the Soundbar 702 plays its correspondingportions of the surround sound audio information.

VII. Example Method

FIG. 9 shows an example method 900 for generating and transmittingsurround sound audio information to satellites for a multichannelsurround sound system according to some embodiments.

Example method 900 describes certain functions performed by a soundbarcomponent, such as Soundbar 702. However, method 900 and/or aspectsthereof could be performed by any other type of device comprising one ormore processors configured to perform the features and functions recitedin method 900, including but not limited to one or more of a differenttype of playback device, a television, a computing device, anaudio/video controller, a set-top box, a media streaming device (e.g.,an AppleTV, Amazon Fire, Roku, or similar), a gaming console, or similardevices now known or later developed, acting individually or in concertwith each other.

Method 900 begins at block 902, which includes, during a first timeinterval, (i) for each playback device in a first set of playbackdevices, generating a first portion of a channel stream for the playbackdevice, and (ii) for each playback device in a second set of playbackdevices, generating a first portion of a channel stream for the playbackdevice.

In some embodiments, the first set of playback devices includessubwoofer and overhead playback devices, such as satellite playbackdevices Sub₁ 710, Sub₂ 712, and Overhead 714 shown in FIG. 7. In someembodiments, the second set of playback devices includes rear playbackdevices, such as satellite playback devices Rear L 716, and Rear R 718shown in FIG. 7.

In some embodiments, block 902 additionally includes, during the firsttime interval, additionally generating a first portion of a channelstream for the soundbar.

Next, method 900 advances to block 904, which includes, during a secondtime interval following the first time interval, (i) for each playbackdevice in the first set of playback devices, generating a second portionof the channel stream for the playback device, and (ii) for eachplayback device in the second set of playback devices, generating asecond portion of the channel stream for the playback device.

In some embodiments, block 904 additionally includes, during the secondtime interval following the first time interval, additionally generatinga second portion of the channel stream for the soundbar.

Next, method 900 advances to block 906, which includes, during a thirdtime interval following the second time interval, (i) for each playbackdevice in the first set of playback devices, generating a third portionof the channel stream for the playback device and transmitting the firstportion and the second portion of the channel stream to the playbackdevice via the LAN and (ii) for each playback device in the second setof playback devices, generating a third portion of the channel streamfor the playback device. In some embodiments, the LAN comprises one ormore of a wireless LAN, a wired LAN, or any other type of LAN now knownor later developed.

In some embodiments, block 906 additionally includes, during the thirdtime interval following the second time interval, additionallygenerating a third portion of the channel stream for the soundbar.

In some embodiments, transmitting the first portion and the secondportion of the channel stream to an individual playback device via theLAN in block 906 comprises (i) generating one or more packets comprisingthe first portion and the second portion of the channel stream andplayback timing for the first portion and the second portion of thechannel stream for the individual playback device, where the playbacktiming specifies a future time at which the individual playback deviceis to play the first portion and the second portion of the channelstream; and (ii) transmitting the one or more packets to the individualplayback device via the LAN.

And finally, method 900 advances to block 908, which includes during afourth time interval following the third time interval, (i) for eachplayback device in the first set of playback devices, generating afourth portion of the channel stream for the playback device and (ii)for each playback device in the second set of playback devices,generating a fourth portion of the channel stream for the playbackdevice and transmitting the second portion and the third portion of thechannel stream to the playback device via the LAN.

In some embodiments, block 908 additionally includes, during the fourthtime interval following the third time interval, additionally generatinga fourth portion of the channel stream for the soundbar.

In some embodiments, method 900 additionally includes receiving surroundsound content comprising surround sound audio information and surroundsound audio object data. In operation, individual channel streams forthe playback devices are based on the surround sound audio informationand surround sound audio object data.

In some embodiments, method 900 additionally includes providing clocktiming information of a clock at the soundbar to the playback devices inthe first set of playback devices and the second set of playbackdevices. In some embodiments, the clock timing information is suitablefor an individual playback device to determine a difference between theclock at the soundbar and a clock at the individual playback device.

In some embodiments, the first time interval, the second time interval,the third time interval, and the fourth time interval have substantiallythe same duration. In some embodiments, the time intervals areconsidered to be of substantially the same duration when each of thetime intervals is within about +/−x % of the same time duration, where xis between about 0-15%. In some embodiments, the time intervals areconsidered to be of substantially the same duration when each of thetime intervals is within about +/−y microseconds of the same timeduration, where y is between about 0-500 microseconds. In someembodiments, each of the first time interval, the second time interval,the third time interval, and the fourth time interval is about 2.9 ms,and an individual portion of the channel stream for an individualplayback device comprises about 5.8 ms of surround sound audioinformation. In some embodiments, each of the first time interval, thesecond time interval, the third time interval, and the fourth timeinterval is z ms, and an individual portion of the channel stream for anindividual playback device comprises about 2z ms of surround sound audioinformation, where z is between about 1.5 to 4.5 milliseconds.

In some embodiments, method 900 additionally includes one or more of (i)during a fifth time interval following the fourth time interval, playingthe first portion of the channel stream for the soundbar; (ii) during asixth time interval following the fifth time interval, playing thesecond portion of the channel stream for the soundbar; (iii) during aseventh time interval following the sixth time interval, playing thethird portion of the channel stream for the soundbar while (iii-a) thefirst subwoofer plays the first portion of the channel stream for thefirst subwoofer and (iii-b) the second subwoofer plays the first portionof the channel stream for the second subwoofer; and (iv) during an eighttime interval following the seventh time interval, playing the fourthportion of the channel stream for the soundbar while (iv-a) the firstsubwoofer plays the second portion of the channel stream for the firstsubwoofer, (iv-b) the second subwoofer plays the second portion of thechannel stream for the second subwoofer, (iv-c) the overhead speakerplays the first portion of the channel stream for the overhead speaker,(iv-d) the rear left speaker plays the first portion of the channelstream for the rear left speaker, and (iv-e) the rear right speakerplays the first portion of the channel stream for the rear rightspeaker.

VIII. Conclusion

The above discussions relating to playback devices, controller devices,playback zone configurations, and media/audio content sources provideonly some examples of operating environments within which functions andmethods described below may be implemented. Other operating environmentsand configurations of media playback systems, playback devices, andnetwork devices not explicitly described herein may also be applicableand suitable for implementation of the functions and methods.

The description above discloses, among other things, various examplesystems, methods, apparatus, and articles of manufacture including,among other components, firmware and/or software executed on hardware.It is understood that such examples are merely illustrative and shouldnot be considered as limiting. For example, it is contemplated that anyor all of the firmware, hardware, and/or software aspects or componentscan be embodied exclusively in hardware, exclusively in software,exclusively in firmware, or in any combination of hardware, software,and/or firmware. Accordingly, the examples provided are not the onlyways) to implement such systems, methods, apparatus, and/or articles ofmanufacture.

Additionally, references herein to “embodiment” means that a particularfeature, structure, or characteristic described in connection with theembodiment can be included in at least one example embodiment of aninvention. The appearances of this phrase in various places in thespecification are not necessarily all referring to the same embodiment,nor are separate or alternative embodiments mutually exclusive of otherembodiments. As such, the embodiments described herein, explicitly andimplicitly understood by one skilled in the art, can be combined withother embodiments.

The specification is presented largely in terms of illustrativeenvironments, systems, procedures, steps, logic blocks, processing, andother symbolic representations that directly or indirectly resemble theoperations of data processing devices coupled to networks. These processdescriptions and representations are typically used by those skilled inthe art to most effectively convey the substance of their work to othersskilled in the art. Numerous specific details are set forth to provide athorough understanding of the present disclosure. However, it isunderstood to those skilled in the art that certain embodiments of thepresent disclosure can be practiced without certain, specific details.In other instances, well known methods, procedures, components, andcircuitry have not been described in detail to avoid unnecessarilyobscuring aspects of the embodiments. Accordingly, the scope of thepresent disclosure is defined by the appended claims rather than theforegoing description of embodiments.

When any of the appended claims are read to cover a purely softwareand/or firmware implementation, at least one of the elements in at leastone example is hereby expressly defined to include a tangible,non-transitory medium such as a memory, DVD, CD, Blu-ray, and so on,storing the software and/or firmware.

What is claimed is:
 1. A soundbar comprising: one or more processors;one or more speaker drivers; one or more network interfaces configuredto communicatively couple the soundbar to a local area network (LAN);and tangible, non-transitory computer-readable media with instructionsencoded thereon, wherein the instructions, when executed, cause thesoundbar to perform functions comprising: during a first time interval,(i) for each playback device in a first set of playback devices,generating a first portion of a channel stream for the playback device,and (ii) for each playback device in a second set of playback devices,generating a first portion of a channel stream for the playback device;during a second time interval following the first time interval, (i) foreach playback device in the first set of playback devices, generating asecond portion of the channel stream for the playback device, and (ii)for each playback device in the second set of playback devices,generating a second portion of the channel stream for the playbackdevice; during a third time interval following the second time interval,(i) for each playback device in the first set of playback devices,generating a third portion of the channel stream for the playback deviceand transmitting the first portion and the second portion of the channelstream to the playback device via the LAN and (ii) for each playbackdevice in the second set of playback devices, generating a third portionof the channel stream for the playback device; and during a fourth timeinterval following the third time interval, (i) for each playback devicein the first set of playback devices, generating a fourth portion of thechannel stream for the playback device and (ii) for each playback devicein the second set of playback devices, generating a fourth portion ofthe channel stream for the playback device and transmitting the secondportion and the third portion of the channel stream to the playbackdevice via the LAN.
 2. The soundbar of claim 1, wherein the functionsfurther comprise: receiving surround sound content comprising surroundsound audio information and surround sound audio object data, andwherein individual channel streams are based on the surround sound audioinformation and surround sound audio object data.
 3. The soundbar ofclaim 1, wherein the LAN comprises one or more of a wireless LAN or awired LAN.
 4. The soundbar of claim 1, wherein the first time interval,the second time interval, the third time interval, and the fourth timeinterval have substantially the same duration.
 5. The soundbar of claim1, wherein each of the first time interval, the second time interval,the third time interval, and the fourth time interval is about 2.9 ms,and wherein an individual portion of the channel stream for anindividual playback device comprises about 5.8 ms of audio.
 6. Thesoundbar of claim 1, wherein transmitting the first portion and thesecond portion of the channel stream to an individual playback devicevia the LAN comprises: generating one or more packets comprising thefirst portion and the second portion of the channel stream and playbacktiming for the first portion and the second portion of the channelstream for the individual playback device, wherein the playback timingspecifies a future time at which the individual playback device is toplay the first portion and the second portion of the channel stream; andtransmitting the one or more packets to the individual playback devicevia the LAN.
 7. The soundbar of claim 1, wherein the functions furthercomprise: providing clock timing information of a clock at the soundbarto individual playback devices in the first set of playback devices andthe second set of playback devices, wherein the clock timing informationis suitable for an individual playback device to determine a differencebetween the clock at the soundbar and a clock at the individual playbackdevice.
 8. The soundbar of claim 1, wherein the first set of playbackdevices comprises a first subwoofer, a second subwoofer, and an overheadspeaker, and wherein the second set of playback devices comprises a leftrear speaker and a right rear speaker.
 9. The soundbar of claim 8,wherein the functions further comprise: during the first time interval,additionally generating a first portion of a channel stream for thesoundbar; during the second time interval following the first timeinterval, additionally generating a second portion of the channel streamfor the soundbar; during the third time interval following the secondtime interval, additionally generating a third portion of the channelstream for the soundbar; and during the fourth time interval followingthe third time interval, additionally generating a fourth portion of thechannel stream for the soundbar.
 10. The soundbar of claim 9, whereinthe functions further comprise: during a fifth time interval followingthe fourth time interval, playing the first portion of the channelstream for the soundbar; during a sixth time interval following thefifth time interval, playing the second portion of the channel streamfor the soundbar; during a seventh time interval following the sixthtime interval, playing the third portion of the channel stream for thesoundbar while (i) the first subwoofer plays the first portion of thechannel stream for the first subwoofer and (ii) the second subwooferplays the first portion of the channel stream for the second subwoofer;and during an eight time interval following the seventh time interval,playing the fourth portion of the channel stream for the soundbar while(i) the first subwoofer plays the second portion of the channel streamfor the first subwoofer, (ii) the second subwoofer plays the secondportion of the channel stream for the second subwoofer, (iii) theoverhead speaker plays the first portion of the channel stream for theoverhead speaker, (iv) the rear left speaker plays the first portion ofthe channel stream for the rear left speaker, and (v) the rear rightspeaker plays the first portion of the channel stream for the rear rightspeaker.
 11. Tangible, non-transitory computer-readable media comprisinginstructions encoded therein, wherein the instructions, when executed byone or more processors, cause a soundbar to perform functionscomprising: during a first time interval, (i) for each playback devicein a first set of playback devices, generating a first portion of achannel stream for the playback device, and (ii) for each playbackdevice in a second set of playback devices, generating a first portionof a channel stream for the playback device; during a second timeinterval following the first time interval, (i) for each playback devicein the first set of playback devices, generating a second portion of thechannel stream for the playback device, and (ii) for each playbackdevice in the second set of playback devices, generating a secondportion of the channel stream for the playback device; during a thirdtime interval following the second time interval, (i) for each playbackdevice in the first set of playback devices, generating a third portionof the channel stream for the playback device and transmitting the firstportion and the second portion of the channel stream to the playbackdevice via a local area network (LAN) and (ii) for each playback devicein the second set of playback devices, generating a third portion of thechannel stream for the playback device; and during a fourth timeinterval following the third time interval, (i) for each playback devicein the first set of playback devices, generating a fourth portion of thechannel stream for the playback device and (ii) for each playback devicein the second set of playback devices, generating a fourth portion ofthe channel stream for the playback device and transmitting the secondportion and the third portion of the channel stream to the playbackdevice via the LAN.
 12. The tangible, non-transitory computer-readablemedia of claim 11, wherein the functions further comprise: receivingsurround sound content comprising surround sound audio information andsurround sound audio object data, and wherein individual channel streamsare based on the surround sound audio information and surround soundaudio object data.
 13. The tangible, non-transitory computer-readablemedia of claim 11, wherein the LAN comprises one or more of a wirelessLAN or a wired LAN.
 14. The tangible, non-transitory computer-readablemedia of claim 11, wherein the first time interval, the second timeinterval, the third time interval, and the fourth time interval havesubstantially the same duration.
 15. The tangible, non-transitorycomputer-readable media of claim 11, wherein each of the first timeinterval, the second time interval, the third time interval, and thefourth time interval is about 2.9 ms, and wherein an individual portionof the channel stream for an individual playback device comprises about5.8 ms of audio.
 16. The tangible, non-transitory computer-readablemedia of claim 11, wherein transmitting the first portion and the secondportion of the channel stream to an individual playback device via theLAN comprises: generating one or more packets comprising the firstportion and the second portion of the channel stream and playback timingfor the first portion and the second portion of the channel stream forthe individual playback device, wherein the playback timing specifies afuture time at which the individual playback device is to play the firstportion and the second portion of the channel stream; and transmittingthe one or more packets to the individual playback device via the LAN.17. The tangible, non-transitory computer-readable media of claim 11,wherein the functions further comprise: providing clock timinginformation of a clock at the soundbar to individual playback devices inthe first set of playback devices and the second set of playbackdevices, wherein the clock timing information is suitable for anindividual playback device to determine a difference between the clockat the soundbar and a clock at the individual playback device.
 18. Thetangible, non-transitory computer-readable media of claim 11, whereinthe first set of playback devices comprises a first subwoofer, a secondsubwoofer, and an overhead speaker, and wherein the second set ofplayback devices comprises a left rear speaker and a right rear speaker.19. The tangible, non-transitory computer-readable media of claim 18,wherein the functions further comprise: during the first time interval,additionally generating a first portion of a channel stream for thesoundbar; during the second time interval following the first timeinterval, additionally generating a second portion of the channel streamfor the soundbar; during the third time interval following the secondtime interval, additionally generating a third portion of the channelstream for the soundbar; and during the fourth time interval followingthe third time interval, additionally generating a fourth portion of thechannel stream for the soundbar.
 20. The tangible, non-transitorycomputer-readable media of claim 19, wherein the functions furthercomprise: during a fifth time interval following the fourth timeinterval, playing the first portion of the channel stream for thesoundbar; during a sixth time interval following the fifth timeinterval, playing the second portion of the channel stream for thesoundbar; during a seventh time interval following the sixth timeinterval, playing the third portion of the channel stream for thesoundbar while (i) the first subwoofer plays the first portion of thechannel stream for the first subwoofer and (ii) the second subwooferplays the first portion of the channel stream for the second subwoofer;and during an eight time interval following the seventh time interval,playing the fourth portion of the channel stream for the soundbar while(i) the first subwoofer plays the second portion of the channel streamfor the first subwoofer, (ii) the second subwoofer plays the secondportion of the channel stream for the second subwoofer, (iii) theoverhead speaker plays the first portion of the channel stream for theoverhead speaker, (iv) the rear left speaker plays the first portion ofthe channel stream for the rear left speaker, and (v) the rear rightspeaker plays the first portion of the channel stream for the rear rightspeaker.